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Opløftning ved Svartsengi fortsætter

Magma flyder højst sandsynligt ikke længere ind i diget, der blev dannet den 14. januar, og at udbruddet er afsluttet. En opdateret farevurdering vurderer stadig, at faren for sprækker i Grindavík er høj

19.1.2024

Opdateret 19. januar 16:30 UTC

 

Der registreres stadig tydelige signaler om en fortsat landhævning under Svartsengi. Det er endnu for tidligt at sige, om hastigheden af ​​landhævningen er steget siden før udbruddet den 14. januar. De første målinger tyder på, at det er tilfældet, men som tidligere skrevet kan målinger svinge fra den ene dag til den anden og en længere tidslinje for måling er nødvendig for at kunne fortolke den langsigtede udvikling af landhævningen.

Seismisk aktivitet fortsætter med at falde i området af magmadiget, og deformationssignaler set på GPS-enheder tyder på en betydelig opbremsning af jordens bevægelse sammenlignet med tidligere dage. Disse oplysninger tyder på, at magma ikke længere strømmer ind i diget, og at udbruddet er afsluttet.

GPS-målinger viser også små deformationer i Grindavík. Der er stadig stor fare for, at jorden kollapser til sprækker i byen, og derfor er det vigtigt at kortlægge nye sprækker og ændringer af kendte estimerede.

Det islandske meteorologiske kontor har opdateret farevurderingen på grund af den vulkanske og seismiske aktivitet. Fareniveauet er blevet reduceret i alle zoner.

En samlet farevurdering for zone 1, Svartsengi, er nu nede på gul (moderat fare).

En samlet farevurdering for zone 4, Grindavík, er nu nede i rødt (høj fare). Bemærk, at farven på zoner repræsenterer den overordnede fare inden for disse zoner. En fare, der vurderes til at være større inden for en zone, er skrevet med fede bogstaver i listen over farer på kortet.

Farevurderingskortet træder i kraft kl. 15:00 i dag, fredag ​​den 19. januar og er gyldigt til torsdag den 25. januar kl. 15:00, medmindre der er væsentlige ændringer.

Hazard_map_IMO_19jan_2024

 

Opdateret 18. januar 15:30 UTC

 

Som rapporteret i nyhederne i går, er der stadig klare tegn på landstigning under Svartsengi, men det er stadig for tidligt at bestemme stigningshastigheden på grund af den seneste vulkanske aktivitet i området. GNSS-målinger evalueres for at give en samlet vurdering af situationen. Det ser dog ud til, at deformationen forbliver magen til den, der blev observeret efter vulkanudbruddet den 18. december.

Omkring 200 jordskælv er blevet registreret nær magmakanalen siden i går, hvor det største måler 1,4 i styrke. Siden midnat er der sket cirka 70 små jordskælv, hvilket er færre end målt dagen før. Vejret har påvirket antallet af jordskælv, der er opdaget i de seneste dage, men antallet af jordskælv ser ud til generelt at være faldet.

Der er fortsat en betydelig risiko i Grindavík på grund af sprækker og potentialet for jordkollaps ind i dem .

Opdateret 17. januar kl. 18:00 UTC

 

 

Magmaophobning fortsætter under Svartsengi. Det er for tidligt at hævde hastigheden af ​​landhævningen kort efter vulkanudbruddet. Eksperter vil fortsat vurdere data fra GNSS-stationer i området for at få en samlet vurdering af situationen. En af målerne, som var placeret nord for Grindavík, gik under lava, men over 20 GNSS-stationer er i området og bliver brugt.

Seismisk aktivitet har været mild over magmakanalen i de sidste 24 timer. Ifølge beregningsmodeller ligger magma lavvandet i den sydlige ende af kanalen, hvor landet ser ud til at være stærkt opbrudt, hvilket gør det lettere for magmaen at nå overfladen. Derfor er der fortsat sandsynlighed for, at nye eruptive sprækker kan åbne sig uden varsel.

Der er stadig fare i Grindavík relateret til sprækker og potentialet for jordkollaps ind i dem. Der er sket betydelige deformationer i forbindelse med graben i den østlige del af byen. Disse bevægelser var for det meste langs de sprækker, der blev dannet den 10. november og allerede var blevet kortlagt.

Gasforurening blev målt i går under arbejde på brønde forbundet til forsyningssystemet i Grindavík. Det islandske meteorologiske kontor overvåger ikke lokal gasforurening i Grindavík. Det skal undersøges nærmere, om gasforureningen er relateret til magmaen, der ligger meget lavt i området. Det skal bemærkes, at farlig gasforurening er blandt de emner, der nævnes i den nuværende farevurdering for Grindavík.

IMO har udsendt et opdateret farevurderingskort. Der er ingen ændringer i den samlede farevurdering for områderne i forhold til tidligere. Kortet træder i kraft klokken 15.00 i dag og gælder til fredag ​​den 19. januar klokken 15.00, medmindre der sker væsentlige udviklinger.

Hazard_map_IMO_17jan_2024

 

Opdateret 16. januar kl. 18:00 UTC

 

Magma fortsætter med at akkumulere under Svartsengi med en hastighed svarende til den, der blev observeret før de sidste to udbrud. Dette var konsensus opnået under et høringsmøde mellem forskere her til morgen. Under udbruddet sidste søndag, i lighed med udbruddet den 18. december, strømmede magma mod øst fra akkumuleringsstedet under Svartsengi, hvilket skabte en magmaledning, der strækker sig fra Stóra-Skógfell sydpå under Grindavík. Beregningsmodeller understøtter denne observation og indikerer, at magmaens oprindelse var lidt længere mod vest sammenlignet med det tidligere udbrud, hvilket førte til variationer i de seneste GPS-målinger sammenlignet med dem, der blev registreret den 18. december.

Da der dannes en magmakanal tæt på overfladen, forspændes jordskorpen, hvilket får landet over den centrale del af kanalen til at aftage og danne en graben. Derudover er jorden forhøjet på hver side af den. Beregningsmodeller, der blev gennemgået på høringsmødet, viser, at GNSS-stationen i Svartsengi er placeret i kanten af ​​kanalen, hvor jorden hæver sig i takt med, at ledningen dannes. Nu, to dage efter kanalens dannelse, forventes Svartsengi GNSS-stationen at vise nedsynkning, hvis magmaakkumuleringen er ophørt. Dette er dog ikke observeret, hvilket indikerer, at magmaakkumulering fortsætter som før.

Magmakanalen, der blev genereret i udbruddet, der begyndte i søndags, ligger lidt længere mod øst end kanalen, der strakte sig under Grindavík den 10. november. Data indsamlet og behandlet af Islands Naturhistoriske Institut og National Land Survey of Iceland afslører, at en ny graben har dannet øst for den, der dukkede op den 10. november. Den nydannede graben måler cirka 800-1000 meter i bredden, som vist på kortet nedenfor. Den største nedsynkning i den er cirka 30 cm, men det er værd at bemærke, at regionen stadig oplever nedsynkninger, og dalen udvides gradvist. Til sammenligning havde graben, der udviklede sig i Grindavík den 10. november, en bredde på omkring 2 km, hvor den mest markante indsynkning målte omkring 1,3 meter.

Inde i denne nyligt dannede graben er tidligere kortlagte sprækker, der var synlige på overfladen, udvidet, og yderligere sprækker er opstået. Følgelig er risikoen forbundet med disse sprækker og muligheden for jordkollaps i dem steget i den østlige del af Grindavík sammenlignet med tidligere.

NyrSigdalur

 

Kort, der viser placeringen og bredden af ​​graben dannet den 10. november (“Mörk sigdals 10-11. nóvember”) og den nyeste graben, der for nylig blev dannet mod øst (“Mörk sigdals 14-15. janúar”).

Opdateret 16. januar kl. 11:45 UTC

 

Der er i øjeblikket ingen synlig aktivitet i de eruptive sprækker, med den seneste lava observeret udgået fra den nordlige sprække kort efter kl. 1 i nat. Seismisk aktivitet fortsætter med at falde, hvilket betyder, at området er ved at stabilisere sig. Omkring 200 små jordskælv blev registreret nær magmakanalen siden midnat, hvilket indikerer, at magma stadig migrerer. Den mest seismiske aktivitet er placeret nær Hagafell, tæt på den første eruptive sprække, der åbnede søndag morgen. På dette tidspunkt er det for tidligt at erklære, at udbruddet er forbi.

GPS-sensorer fortsætter med at registrere jorddeformation i og omkring Grindavík, hvilket illustrerer, at magmakanalen under Grindavík stadig forårsager udvidelse i området. Termiske billeder fra en drone i aftes viser, at sprækker, der tidligere er kortlagt sydvest for Grindavík, er blevet betydeligt større. Der er fortsat betydelige farer i området.


 

Opdateret 15. januar kl. 16:40 UTC

 

Based on webcam footage, it is evident that the lava flow has decreased from the eruptive fissures that opened yesterday. Flow from the southern eruptive fissure, which emerged around noon yesterday near the town‘s border, seems to have ceased. The majority of the remaining lava flow is now directed southwest along the protective barriers, and its trajectory seems to have stabilized.

It is difficult to estimate how long this eruption will last. Seismic activity has decreased, and GPS measurements indicate that the rate of deformation in the area has reduced. However, deformation is still detected near the southernmost part of the magma conduit beneath Grindavík.

Measurements indicate that there has been a displacement of up to 1.4 meters in the past 24 hours, distributed across numerous fissures within the town‘s boundaries. Fresh fissures have developed, and existing ones have expanded. It is possible that additional fissures may emerge on the surface in the next few days.

As previously stated, the eruption sites are extremely hazardous, and the possibility of new fissures emerging without warning cannot be dismissed. This was demonstrated by the eruptive fissure that appeared near the border of Grindavík yesterday, which provided no recognizable warning signs on the monitoring equipment.

Today, there is a mild wind from the northeast at the eruption sites, but it will pick up speed later in the day. Therefore, gas pollution is drifting southwest towards the ocean. Tomorrow, the area will experience winds from the north reaching 10-18 m/s, causing the gas to drift south. Refer to the weather service’s forecast for gas dispersion details.

The Icelandic Meteorological Office continues to monitor the area and is in direct contact with civil protection and response teams in the region about the progression of the event.

Scientists met this morning for a consultation meeting organized by the Icelandic Meteorological Office. They reviewed the most recent data related to the eruption.Top of Form

In the upcoming days, there will be ongoing measurements and the collection of additional data, followed by analysis. These data are being utilized, among other things, to construct models that enhance comprehension of the pre-eruptive indicators that led up to this event and to evaluate the most likely progression of the eruption. Comparisons are also being made between the December 18 eruption and the eruption that began yesterday to enhance understanding of changes in the area and to evaluate the most likely scenarios going forward.

The Icelandic Meteorological Office has issued an updated hazard assessment map based on the latest data. It remains unchanged from the last update. The map is valid until 19:00 on Wednesday, January 17, unless new developments arise.

Hazard_map_IMO_15jan_2024

 

Kort_Hraundreifin_Maelingar140120224

Kort, der viser lavaens udbredelse baseret på målinger udført af det islandske naturhistoriske institut og Islands Universitets institut for geovidenskab. Der blev gennemført undersøgelser to gange i går. Den mørkelilla form viser udstrækningen af ​​lavaen kl. 13.50 den 14. januar, mens den lyse lilla form viser udstrækningen kl. 16.15, næsten 2,5 timer senere. De eruptive sprækker er markeret med røde linjer, mens barriererne konstrueret for at forhindre lava i at nå Grindavík er repræsenteret af orange stiplede linjer

ThykktHrauns_15012024

Kort, der viser tykkelsen af ​​lavastrømmen baseret på målinger kl. 13:50 i går.

Opdateret 14. januar kl. 15:30 UTC

 

 

Udbruddet nær Hagafell-Grindavík har bevaret samme styrke den seneste time eller deromkring.

Seismiske målinger viser, at ved begyndelsen af ​​urolighederne i morges (~2:30 om morgenen), bevægede den magmafyldte digeindtrængen sig først fra den SE-kant af Stóra-Skógfell og fortsatte derefter sydvest til den sydlige ende af Grindavík. Klokken 05.30 havde seismiciteten nået den nordlige ende af Grindavík, og både seismicitet og deformationsmålinger indikerer, at diget siden har forplantet sig under Grindavík by. En ny eruptiv sprække åbnede kl. 12:10 i eftermiddags, lige nord for byen. Lavastrømme ekstruderet fra denne sprække er nu kommet ind i byen.

På grund af digets udbredelse blev eksisterende forkastninger og sprækker reaktiveret, og der er sandsynligvis dannet nye sprækker i Grindavík.

 

Gas distribution

Det islandske meteorologiske kontors vejrudsigt for gasfordeling fra udbruddet ved Hagafell indikerer, at retningen er nord og nordøst, med en hastighed på 3-8 m/s, og vejret er tørt og lyst i dag. Det bliver til tider overskyet med mindre snefald sent i aften og i morgen tidlig. Det vil klare op om eftermiddagen i morgen. Forureningen fra udbruddet breder sig mod syd og sydvest.
GrindavikGas14Jan--002-

 

Nyt farekort udgivet

Det islandske meteorologiske kontor har opdateret farevurderingskortet i lyset af fortolkningen af ​​de seneste data.

Risikoen er steget på alle områder. Farevurderingskortet er gyldigt indtil kl. 19.00, mandag den 15. januar, medmindre andet er angivet.

Hazard_map_IMO_14jan_2024

Opdateret 14. januar kl. 8:20

 

Et udbrud startede klokken 7:57 UTC

Sprækkeåbningen er sydøst for Hagafell-bjerget.

Den sydligste del af sprækken er omkring 900 m fra byen Grindavík.

Åbningen er syd for lavastrømsafbøjningsbarrierer, der bygges nord for Grindavík. Lava strømmer nu mod byen.

Kort_StadsetningGoss2Et billede taget ombord på kystvagtens fly. Sprækkeåbning kan ses med lysene i Grindavík i det fjerne. Et kort, der viser sprækkeåbningen markeret med en rød linje.Kort_StadsetningGoss3

 

Opdateret 14. januar kl. 06:15 UTC

Omkring 03:00 UTC i dag begyndte en intens serie af jordskælv ved Sundhnúksgígar-kraterrækken. 

På tidspunktet for offentliggørelsen er der målt over 200 jordskælv i området, og seismiciteten har bevæget sig mod byen Grindavík. 

So far, the largest recorded earthquake is 3.5 in magnitude, and it was measured at 04:07 UTC at Hagafell. 

Both real-time GPS measurements and borehole pressure readings (from HS Orka) show major changes since the onset of today’s earthquake activity. These observations, in addition to the ongoing seismicity, confirm that magma is moving within the region. 

Our assessment is that the possibility of an eruption is high, and that it could occur imminently.

Skjalftar_1401_Midn

A map showing the latest earthquake activity.

Updated 12 January at 17:45 UTC

 

The Icelandic Meteorological Office has updated the hazard assessment map for the Grindavík – Svartsengi region due to the ongoing unrest on the Reykjanes Peninsula. As before, the map shows an assessment of existing hazards that could occur with little warning within the specified regions. Note that the assessment applies only for hazards within the defined areas, although hazards are possible beyond the confines of the assessed regions.

In terms of colour-coding, the overall assessment for the six zones remains unchanged from the previous map. However, there is a change in the hazard assessment associated with fissures within Grindavík (zone 4). The hazards associated with sudden opening of mapped and unknown fissures within Grindavík is now deemed higher. It should be noted that the hazards associated with fissures is limited to known areas within the municipal boundaries.

Unless otherwise stated, the map is valid until Tuesday, 16 January 2024.

Hazard_map_IMO_12jan_2024

 

Updated 9 January at 13:00 UTC

 

Seismic activity continues to exhibit a pattern similar to that of recent days. The earthquake activity remains relatively low, primarily centered between Hagafell and Stóra Skógfell, where the center of the intrusion is situated. Additionally, there is ongoing seismic activity in Fagradalsfjall, persisting since December 18th.

Land uplift is still being measured in the Svartsengi area, exhibiting a relatively stable trend since the eruption on December 18th. The accompanying image, marked with red dots representing data from the GPS station SENG in Svartsengi, illustrates this trajectory The recent rate of uplift is approximately 5 mm per day, resulting in a current elevation that is about 5 cm higher than before the dike intrusion on November 10th and December 18th last year.

Calculations from models relying on deformation measurements (GPS and satellite images) indicate that the amount of magma accumulated in the reservoir beneath Svartsengi has reached a level comparable to the volume that led to the formation of the magma conduit and the subsequent eruption on December 18th last year. This suggests that there is an increased risk of an eruption in the coming days.

The Icelandic Meteorological Office issued an updated hazard map on January 5th, and it will be reassessed on January 12th.

SENG-9-jan-

 

Relative målinger fra GPS-stationen SENG i Svartsengi fra begyndelsen af ​​oktober 2023 til i dag, viser nord-, øst- og lodrette komponenter (top, midt, bund). Den nederste kurve viser landhævningen i millimeter, med dagens måling angivet med en grøn prik.

Opdateret 5. januar kl. 17:40 UTC

 

Et nyt farekort er udstedt af IMO. Kortet afspejler en farebaseret vurdering af Grindavík – Svartsengi-regionen, foretaget den 5. januar 2024. Farevurderingen er baseret på de seneste overvågningsdata, herunder seismisk aktivitet og jorddeformation, samt geodætiske modelleringsresultater. Vurderingen tager også højde for sandsynligheden for vulkanske farer i hver af de seks zoner, som vist på kortet.

I dagens vurdering påvirker hovedændringen Svartsengi-regionen (zone 1), som nu anses for at være på et moderat fareniveau, hvilket afspejler et fald i forhold til den tidligere version af farekortet. Begrundelsen for denne ændring er, at farevurderingen på grund af dannelsen af ​​større overfladebrud er faldet, da der ikke er dannet nye større brud på det seneste. Derudover gør de seneste geofysiske observationer sammen med vores videnskabelige konsensus Sundhnúksgígar til det bedste sted for et udbrud.

I mellemtiden fortsætter IMO med at overvåge området, og eventuelle ændringer vil blive kommunikeret direkte til civilbeskyttelsen via de sædvanlige kommunikationskanaler.

 

Hazard_map_IMO_5jan_2024

Opdateret 5. januar kl. 14:30 UTC

 

Landhævningshastigheden nær Svartsengi fortsætter med at falde. Eksperter samlet på Meteorologisk Kontor her til morgen bekræftede dette gennem en analyse af GPS-data. Som tidligere rapporteret, signalerer dette en stigning i magmatrykket, hvilket øger sandsynligheden for et nyt digeindtrængen og potentielt udbrud. Det kan dog ikke udelukkes, at dette alternativt kan tyde på et fald i magmatilstrømningen.

Cirka 490 jordskælv har fundet sted nær magmakanalen siden tirsdag den 2. januar. Blandt disse havde 14 en styrke på over 1,0, hvoraf det største målte 1,8 nord for Hagafell. Onsdag den 3. januar indtraf et jordskælv med en styrke på 4,3 nær Trölladyngja, kort efterfulgt af et jordskælv med en styrke på 3,5 og adskillige efterskælv; omkring 900 jordskælv er blevet målt i området.

Den seismiske aktivitet nær Trölladyngja den 3. januar fandt sted langs en anerkendt brudlinje, hvor større jordskælv tidligere er sket flere gange. Der er intet, der tyder på, at disse jordskælv er direkte forbundet med magmabevægelser. Ikke desto mindre er de bemærkelsesværdige ændringer i landskabet i forbindelse med vulkansk aktivitet i Fagradalsfjall, landhævningen nær Svartsengi, magmakanalen nær Sundhnúk den 10. november og udbruddet den 18. december blevet målt på tværs af det vestlige Reykjanes og påvirker seismisk aktivitet i hele regionen .

According to their evaluation, scientists conclude that in the event magma reaches the surface, the most probable site for a subsequent eruption would again be Sundhnúksgígaröðinni, situated between Stóra-Skógfell and Hagafell. However, it is important to remember that dike intrusions do not always culminate in an eruption, as evidenced by the activity at Fagradalsfjall and also during the Krafla fires. 

 

Updated 3 January at 12:30 UTC

At 10:50 AM, an earthquake of magnitude 4.5 occurred near Trölladyngja, followed shortly by another earthquake measuring 3.9 at 10:54 AM and a series of aftershocks. The earthquakes occurred at a depth of approximately 5 km and were likely triggered in response to stress released from earth movement elsewhere on the Reykjanes Peninsula. These earthquakes were widely felt in the southwest region of Iceland.

The location of the earthquakes is about 20 km NNE of Svartsengi, where land rise due to magma accumulation is ongoing. 

The accompanying image shows the location of the earthquake that occurred at 10:50 AM and its impact area.

Gikkskjalftar-trolladyngja-3-jan

Updated 2 January at 14:00 UTC

 

The rate of ground displacement at Svartsengi is decreasing. Experts gathered at the Meteorological Office this morning confirmed this through an analysis of GPS data.

The deceleration of inflation is an indication that magma pressure is rising, increasing the chances of new dike intrusion and also volcanic eruption. This is a similar change in ground displacement that was observed at the end of the day on December 15, which culminated in an eruption three days later. However, it is difficult to assert whether this pattern will repeat.

The first signs of an impending volcanic eruption are a sudden increase in seismic activity, and such signs were observed shortly before the eruption began on December 18.

In recent days, seismic activity in the area has been relatively consistant, with around 200 earthquakes recorded per day. Most of the earthquakes measure below magnitude 1.0, but around 30 earthquakes with magnitudes exceeding 1.0 have been recorded since December 29, with the largest being a magnitude 2.1 located in the northern part of Grindavík.

Continued scientific assessment indicates that, should an eruption occur, the Sundhnúkur crater row, between Stóra-Skógafell and Hagafell, is the most probable location for an eruption. However, it is important to note that magma migration does not always result in an eruption, as demonstrated by the activity at Fagradalsfjall and in the Krafla Fires.

The hazard assessment map issued by the Meteorological Office onDecember 29 remains unchanged and is valid until January 5.

Seismic activity continues to be measured west of Fagradalsfjall, where around 100 small earthquakes have been recorded since December 29. Further analysis of the monitoring data will soon be conducted to obtain a clearer picture of the situation at Fagradalsfjall.

 

Updated 29 December at 15:15 UTC

The ground continues to inflate at Svartsengi. At the GPS station Svartsengi (SENG), the land has now reached a similar height as measured just before the eruption on 18 December. The rate of uplift since 18 December has remained constant, which is different from the situation before the last eruption, where uplift slowed in the days before the eruption. However, it is difficult to assert that the uplift will slow down before the next eruption, though this has been the case in eruptions on the Reykjanes Peninsula in recent years, and it was also noted during the Krafla Fires. Uncertainty remains about how much magma pressure needs to build up before magma starts moving towards the surface.

The current uplift is not accompanied by as much seismic activity as before. The reason for this is that significant stress in the area was released during the events on 10 November and 18 December. Therefore, considerably more magma needs to accumulate before seismic activity increases from its current level. Before the last eruption, there were several earthquakes over magnitude 3 and one over magnitude 4. Similar seismic activity can be expected in connection with the next magma intrusion.

As magma accumulation continues under Svartsengi, the likelihood of another magma intrusion and an eruption increases with each passing day. It is most likely that the next eruption will occur in the Sundhnúkur, between Stóra-Skógfell and Hagafell. It is important to note that magma intrusions do not always lead to an eruption, as shown by the activity at Fagradalsfjall and in the Krafla Fires.

The Icelandic Meteorological Office has issued an updated hazard map, based on the joint interpretation of data at a status meeting held today, 29 December. The overall assessment of hazard levels within the areas remains unchanged from the last update. However, changes have been made to the list of potential hazards within area 4, Grindavík, where risks due to possible lava flow and gas pollution have been added. The changes are due to increased chances of an eruption north of Grindavík. This hazard map will be reviewed on 5 January 2024.

In the meantime, IMO continues to monitor the area and any changes will be communicated directly to civil protection via the usual communication channels.

Haettusvaedi_VI_29des_EN-2

Updated 27 December at 14:20 UTC

Since 22 December, around 730 earthquakes have been recorded in the vicinity of the magma intrusion, of which 40 had a magnitude above M1. The largest earthquake over this period had a magnitude of 2.1 on 26 December, north of Hagafell. Most of the earthquakes are occurring at a depth of 4 km. Additionally, between 22 December and today, around 140 earthquakes have been located on the western side of Fagradalsfjall. Five of these earthquakes were above M1 in size and the overall depth range was 4 to 7 km.

Ground deformation continues in the Svartsengi region, and the rate of deformation is now similar to before the eruption on 18 December 2023. This means that magma continues to accumulate under Svartsengi. Therefore, it is increasingly likely that another magma intrusion will occur, possibility leading to a second volcanic eruption. Geodetic modelling results indicate that over 10 million m3 of magma were sourced from beneath Svartsengi to feed the intrusion that formed on 18 December, which led to the eruption. Based on the ongoing uplift rate, it will take one to two weeks for the same amount of magma to accumulate again underneath Svartsengi. There is still significant uncertainty on when the built-up in magma pressure will be sufficient to trigger the next magma intrusion.

It should be noted that the original magma intrusion, which formed on 10 November, extended 15 km from Kálfafellsheiði in the north to the southwest of Grindavík, just offshore. This means that magma propagated at depth beneath the entire area, including the town of Grindavík. However, the most likely source area for the next eruption is between Stóra-Skógfell and Hagafell. Based on insights from the December 2023 eruption, the likelihood for the next event increases day by day. 

The hazard assessment map issued on 22 December 2023 remains valid. Assuming an unchanged situation, a new map will be issued on 29 December.

SENG-27-des-2023

Time-series of continuous GPS solutions from station Svartsengi (SENG). The graph shows ground displacements in three components over the past 90 days. From bottom to top they are: up, east, and north, all measured in millimetres. The blue, vertical line shows the timing of the 10 November magma intrusion, and the red line the volcanic eruption on 18 December 2023. Each data point represents a 24-hour solution, and the vertical component shows clearly the ongoing ground uplift at Svartsengi.

Updated 22 December at 17:00 UTC

As announced yesterday, the fissure eruption at Sundhnúksgígar has ended. This indicates a temporary cessation of eruptive activity. In the last 24 hours, nearly 90 earthquakes were recorded in the Grindavík, Sundhnúksgígar, and Svartsengi regions. The largest earthquake was M1.6 west of Hagafell, just after 16:00 UTC yesterday (21 December). Overall, seismicity levels are low but variable on a daily basis.

According to GPS and satellite-based measurements, ground uplift in the Svartsengi region was apparent immediately after the eruption began on the evening of 18 December. Initial measurements show that the rate of uplift is greater than before the eruption occurred. This signifies that magma accumulation continues unabated beneath Svartsengi. This development will likely lead to another dike intrusion and, ultimately, a volcanic eruption. In the event of an eruption, the most likely source region is between Stóra-Skógfell and Hagafell.

Continuous GPS measurements show that the rate of daily ground uplift at Svartsengi between 10 November, when the magmatic intrusion formed, and 18 December progressively declined. This process is likely to repeat itself, meaning that the next dike intrusion could begin with little warning when the uplift rate decreases again. Therefore, the likelihood of an eruption increases day-by-day.

Following confirmation of the end of the 18 December eruption, the Icelandic Meteorological Office has issued a new hazard assessment. The hazard map comes into effect at 16:00 UTC today (22 December), and it remains valid until 18:00 UTC on 29 December. The main changes affect zones 2 and 3, where hazard levels have reduced from very high (purple) to high (red). The hazard assessment for all other zones is unchanged. Notably, the assessment for Grindavík is unchanged from the previous map, and the hazard level remains considerable. We emphasise that conditions can change rapidly, and that weather conditions can significantly affect the sensitivity of our monitoring networks. Under such conditions, the warning time could shorten considerably.

The weather forecast for Grindavík on 23 December calls for northeast wind 10-15 m/s, intermittent snowfall, and possibly drifting snow. Temperatures will be low, between 3 to 5°C. On 24 December, winds from the north 13-18 m/s with occasional snow showers, but 10-15 m/s in the afternoon with decreasing snow showers. Intermittent drifting snow can be expected. Temperatures will be from 0 to 2°C


Haettumatskort-22-desember-2023-enska-

The latest hazard assessment map, published on 22 December, 16:00 UTC. It is important to note that new hazards could arise with little warning within the specified areas. Additionally, the assessment applies only to the specified areas, whereas hazards could extend or occur beyond the identified zones.

Updated 21 December at 12:55 UTC

Scientists who flew over the eruption site this morning confirm that no eruptive activity is visible and that lava flow from the craters seems to have ceased. Glowing is still visible in the lava field, possibly within closed channels. This was also confirmed by an Elfu staff member in Sýlingarfell. The activity appears to have diminished late last night or very early this morning. However, it is still possible that lava is flowing in closed channels, so it is premature to declare the eruption over.

Earthquake activity has continued to decrease, and over the last 24 hours, approximately 70 minor earthquakes were measured over the magma conduits. The largest quake yesterday occurred at 14:27 and measured 1.4 in magnitude, while the largest since midnight last night was magnitude 1.9. Deformation measurements at Svartsengi show little movement, but measurements over the next few days will further clarify the situation there.

Gas dispersion, mainly due to the degassing of the lava field, will be southeastward and out to sea today. Tomorrow, with a slower northeast wind, the gas will travel southwest.

At this point, it is difficult to predict the continuation of the eruption, but scientists at the Meteorological Office are constantly assessing the latest data and continue to closely monitor the area.


Updated 20 December at 18:50 UTC

The eruption that began in the Sundhnúksgígar crater row on 18 December started with considerable force, and the warning period was short. About 90 minutes passed from the first signs of seismicity until the eruption began. The eruption occurred on the magma intrusion that formed on 10 November. The magma is sourced most likely from beneath Svartsengi, where the land has risen repeatedly since 2020.

In the last 24 hours, the highest activity in the eruption has remained around the middle of the fissure that opened on 18 December. Seismic activity has been relatively steady, and there have been little changes in deformation since the eruption began. Considering this, the Icelandic Meteorological Office (IMO) assesses that the likelihood of a new eruption forming without warning nearby Grindavík has decreased. Therefore, IMO has issued a new hazard assessment map that will take effect tomorrow, Thursday, 21 December at 7:00 UTC. The hazard assessment map is valid until 28 December. It should be noted that although the likelihood of vent formation within area 4 has decreased, the hazard level in that area is nevertheless considered substantial. Even though the activity has decreased since the eruption began, the intensity of the eruption is still significant and comparable to eruptions at Fagradalsfjall. It has also been shown that the magma can reach the surface quickly, leaving little time to issue warnings.

Hazard_map_VI_20des_DRAFT

Because of the volcanic eruption that began at Sundhnúksgígar crater row on 18 December, there is an increased likelihood of further vent openings on the original fissure. Based on the sudden onset of the eruption at Sundhnúksgígar, the warning time for new fissure openings could be very short.


Updated 20 December at 17:00 UTC

The vigor of the eruption continues to diminish. New images of the area show that currently two craters are erupting. The most active today is the crater directly east of Sýlingarfell which is the southernmost of the craters that were active yesterday.

Lava continues to mostly flow east from the volcanic vents, but a lava tongue has also run west, north of Stóra-Skógfell. The southernmost edge of the lava does not appear to be advancing. Satellite images taken last night show that the lava field is about 3.7 square kilometers in size.

Wind will turn northwesterly tonight and tomorrow, and pollution will be transported southeastward and out to sea. The Icelandic Meteorological Office regularly issues gas pollution forecasts.

There has been a significant decrease in earthquake activity, and over the last 24 hours, about 80 small tremors have been measured over the magma conduits. The largest quake was 2.2 in magnitude at 10:55 am yesterday morning, and the largest since midnight is 1.2 in magnitude.

Hraunflaedi-20-des

Updated 19 December at 18:30 UTC

The eruption continues to weaken. New aerial images of the area show that there are now three vents erupting southeast of Stóra-Skógfell, down from the previous five. The lava has mostly flowed east from the eruption site, but there is also a lava tongue flowing west from the region north of Stóra-Skógfell.

Since the eruption began, about 320 earthquakes have been measured over the magma channels. The largest earthquake, with a magnitude of 4.1, occurred at 23:25 on Monday. After midnight, seismic activity significantly decreased, and since 12:00 today, only 10 earthquakes have been recorded in the region. Following the eruption at Sundhnúksgíga, the land in Svartsengi subsided more than 5 cm. Previously, the land had risen there by about 35 cm since the formation of the magma channel on November 10. It is too early to determine if magma will continue to accumulate under Svartsengi and whether the land will start to rise again.

While the eruption continues at Sundhnúksgíga, there is an increased likelihood that more vents may open along the original fissure as well as further north or south. Looking back at the lead-up to the eruption reveals that there were approximately 90 minutes between the first indicators and the start of the eruption. Therefore, the warning time for new vent openings at Sundhnúk could be very short.


Updated 19 December at 14:30 UTC

The size of the volcanic eruption at Sundhnúksgígar continues to diminish. The lava flow is estimated to be about one-quarter of what it was at the beginning of the eruption on 18 December, and a third of the original fissure is active. The lava fountains are also lower than at the start of the eruption, reaching about 30 meters at their highest. These figures are based on visual estimates from a reconnaissance flight early on 19 December.

The development of the eruption is similar to recent eruptions at Fagradalsfjall, where the fissures are starting to contract and form individual eruption vents. Presently, there are about five eruption vents spread along the original fissure.

According to information from scientists who went on a second helicopter flight with the Icelandic Coast Guard at around 04:00 UTC today, the total length of the fissure eruption has not changed much from the beginning. There was little activity at the southern end of the fissure near Hagafell, and the majority of the lava flow is heading east towards Fagradalsfjall. Two streams reach west, both north of Stóra-Skógfell.

At the time of publication, the volcanic plume is drifting from the west and northwest. Gas pollution might be noticeable in Vestmannaeyjar today, but not elsewhere in populated areas. According to the weather forecast, gas pollution might be detected in the capital area late tonight or tomorrow morning.

A new hazard assessment map is being prepared, and it will be published later today.

Iceye-19-des-nytt

Amplitude image from an ICEYE satellite acquired at 03:11 this morning (19 Dec. 2023). Preliminary analysis of this image show the new eruptive fissure (yellow line) and lava flow (colored area). Notice that he dams built around Svartsengi are clearly visible.

Updated 19 December at 3:00

The intensity of the volcanic eruption, which started about four hours ago, is decreasing. This is evident from seismic and GPS measurements. The fact that the activity is decreasing already is not an indication of how long the eruption will last, but rather that the eruption is reaching a state of equilibrium. This development has been observed at the beginning of all eruptions on the Reykjanes Peninsula in recent years.

The eruptive fissure is about 4 km long, with the northern end just east of Stóra-Skógfell and the southern end just east of Sundhnúk. The distance from the southern end to the edge of Grindavík is almost 3 km.

The Icelandic Meteorological Office continues to monitor the activity and is in direct contact with civil protection and response units in the area. A meeting of scientists will be held tomorrow morning to evaluate the overnight development of the eruption.

This news will be updated at 09:00 on 19 December.

Eldgos_19des_stadsetning_0300_DA


Updated 19 December at 02:10

According to the latest aerial observations and seismicity, the eruption fissure is expanding to the south. At the time of publication, the southern end of the fissure was close to Sundhnúkur. 

The eruption is located on the dyke intrusion that formed in November. The rate of lava discharge during the first two hours of the eruption was thought to be on a scale of hundreds of cubic metres per second, with the largest lava fountains on the northern end of the fissures. 

Lava is spreading laterally from either side of the newly opened fissures. From real-time GPS measurements, significant ground deformation has accompanied the opening of the eruption fissures. 

Since midnight on 19 December, the level of seismicity at the eruption site has decreased. Additionally, estimates of fissure lengthening suggest that the eruption has decreased in intensity since its onset at 22:17 on 18 December.


Updated 18 December at 23:00

 

At 22:17 this evening, a volcanic eruption began north of Grindavík on the Reykjanes peninsula. The eruption is located close to Sundhnúkagígar, about four kilometres northeast of Grindavík, and it can be seen on nearby web cameras. The eruption was preceded by an earthquake swarm that started at 21:00.

 

A Coast Guard helicopter will take off shortly to confirm the exact location and size of the eruption.

More information will be available soon.


Updated 16 December at 14:00 UTC

At this stage it is too early to say if magma accumulation at Svartsengi has stopped and the inflation is over. The rate of deformation has decreased somewhat in recent days, but more data is needed to interpret the possible development of the activity in Svartsengi.

Scientists will continue to analyze the data in the coming days. 

A new hazard map will be released on Wednesday December 20th, which will reflect the interpretation of the latest data.


Updated 15. December at 13:00 UTC

Generally weak seismicity continues in the area affected by the dike and is mostly concentrated near Hagafell.  Since Tuesday December 12, 460 earthquakes, 30 of which were greater than M1.0, have been measured. The largest earthquake in this time was M2.8 near Hagafell on Tuesday morning. Data from GPS stations and satellite images show that uplift due to the accumulation of magma continues around Svartsengi. While magma continues to accumulate in this area, further dikes or an eruption remain possible.

The hazard map published on December 6 Icelandic map here below continues to be valid until December 20. Conditions inside and outside the demarcated hazard zones can change with little warning.

Haettusvaedi-13des-png


Updated 13. December at 11:15 UTC

The area around Svartsengi continues to inflate. The rate of inflation has decreased somewhat since Friday, but it is still greater than it was prior to the formation of the dike that traveled under Grindavík November 10 .

While magma continues to accumulate around Svartsengi, further dikes or an eruption remain possible.

If another dike forms it is considered to be likeliest that it would follow the same path as the November 10 dike. The most likely location for a potential eruption under these conditions is assessed to be north of Grindavík in the direction of Hagafell and the area around Sundhnúkagígar. 

Seismic activity continues at a similar level to the previous days. It is generally weak and mostly in the area around Hagafell.


Updated 6. December at 18:00 UTC

Latest geodetic modelling results suggests that the magma inflow to the dike that formed on November 10 has likely ceased. The chances of an eruption happening along the dike at this time have therefore significantly decreased. However, magma accumulation continues beneath Svartsengi.  

The ongoing activity at Svartsengi, which began in October, is not yet over and a new chapter may have begun with an increased chance of a new magma propagation and, subsequently, increased likelihood of an eruption. 

As previously mentioned, the dike beneath Grindavík was fed by magma accumulating beneath Svartsengi. It is likely that this sequence of events will repeat. When looking at the overall pattern with repeated magma accumulation, it can be estimated that the next magma propagation from Svartsengi might be on a smaller scale than the one previously formed on November 10. A magma propagation could persist for several hours or days with an increased risk due to seismic activity and deformation during that period. 

Signs of a magma propagation include a sudden increase in seismic activity and rapid changes in ground deformation. These signs can be observed on instruments several hours before the magma propagation is likely to pose a threat to Svartsengi or Grindavík. If a magma propagation occurs, the Icelandic Meteorological Office will immediately activate response plans for public safety. 

Following a magma propagation, the likelihood of an eruption increases. As mentioned above, it is most likely that magma will propagate from Svartsengi into the previously formed dike on November 10. Making it the most likely area for an eruption. 

It is not possible to estimate when the next magma propagation will occur. The uncertainty is considerable, and a magma propagation could happen in the next few days or possibly after several months. 

The Icelandic Meteorological Office continues to monitor the area closely and continues to monitor any signs of magma propagation and other changes that could pose further danger in the area near Svartsengi and Grindavík.

Comparison of Svartsengi and Krafla Fires

In the last week, approximately 300-500 earthquakes were detected in a 24-hour period around the dike intrusion. The largest earthquake was a M2.7 near Hagafell on Friday evening. Since midnight today, about 90 earthquakes have been detected along the dike, all measuring below a M2.0. The majority of seismic activity continues to be concentrated along the middle of the dike at about 3-4 km depth. Due to subsidence in Svartsengi the stress in the Earth’s crust has changed. Until the previous stress level is reached, it can be expected that minor seismicity continuous in the region.

Despite the recent decrease in seismic activity in the last weeks, further unrest can be expected on the Reykjanes Peninsula. Examples of similar unrest can be seen in the Krafla Fires that began in 1975. Over a 10-year period, there were 20 magma propagations, with 9 of them resulting in an eruption (see explanatory image below). In the Krafla Fires, all of the magma propagations fed the same dike but they varied in size. A similar recurrence can also be observed in the activity around Fagradalsfjall.

De seneste geodætiske modelleringsresultater indikerer, at mængden af ​​magma, der i øjeblikket er akkumuleret under Svartsengi, er betydeligt mindre end volumen akkumuleret før digets indtrængning den 10. november. Når man ser på magma-akkumuleringen og magma-udbredelsen i Krafla-brandene, er det tydeligt, at den største mængden af ​​magma havde ophobet sig i Krafla-calderaen før det første vulkanudbrud. En mindre mængde magma akkumulerede i calderaen, før den næste magma-udbredelse fandt sted. Det kan estimeres, at en lignende udvikling vil ske i forhold til magmaophobning under Svartsengi, og der skal ophobes en mindre mængde magma, før den udløser den næste magmaudbredelse ind i diget. Det er sandsynligt, at langsomt stigende seismicitet vil blive opdaget, før en ny magmaudbredelse finder sted, hvilket indikerer øget tryk under Svartsengi.

Kroflueldar-enska

Billedet viser samspillet mellem dannelsen af ​​diger og løft midt i Krafla-krateret. Det nederste billede viser højden af ​​land inden for Krafla-krateret, mens det øverste viser afstanden mellem Krafla-krateret og urolighederne. (Páll Einarsson og Bryndís Brandsdóttir, 2021)

Opdateret 1. december kl. 16:50 UTC

 

Seismiciteten på halvøen fortsætter med at falde. I de sidste par dage har det automatiske jordskælvslokaliseringssystem registreret relativt få jordskælv, for det meste mikrojordskælv under størrelsesordenen 1. Den seneste seismicitet er koncentreret i området mellem Sýlingarfell og Hagafell, hvor diget højst sandsynligt fødes af magma, der ophobes under Svartsengi. Nogle deformationer detekteres stadig på cGPS-stationerne tæt på diget, men signalet tolkes nu hovedsageligt som skorpens reaktion på den igangværende inflation i Svartsengi-området.

Selvom aktiviteten langs diget og dets omegn nu foregår med meget lav intensitet, fortsætter inflationen, som startede i Svartsengi få dage efter digets dannelse, med et nogenlunde stabilt tempo. Nogle cGPS-stationer omkring Svartsengi og Mt. Þorbjörn viser en langsom faldende tendens, men andre stationer viser stadig en konstant tendens, hvilket tyder på, at indstrømningshastigheden af ​​magma i dybden ikke er reduceret væsentligt.

Processen, der begyndte den 25. oktober med en betydelig seismisk sværm og toppede den 10. november med dannelsen af ​​et 15 km langt magmatisk dige, er ikke slut. Med sikkerhed kan det konstateres, at en fase er startet, hvor et lignende hændelsesforløb kan gentage sig med tiden.

På dette stadium er det dog svært at sige, hvornår den næste energiske indtrængen af ​​magma på lavere dybde kan forekomme, og om den vil forekomme i et lignende område eller ej. IMO fortsætter med at opretholde overvågningen af ​​området på et højt niveau.

 

Opdateret 29. november kl. 17:00 UTC

The seismic activity has continued to slowly decrease over the last two days. Yesterday, about 340 earthquakes were measured near the magma intrusion in the area east of Sýlingarfell, and since midnight today, around 150 earthquakes have been recorded. Most of the earthquakes have been smaller than magnitude 1.0.

The rate of uplift near Svartsengi has been decreasing, but it is still ongoing at a rate of about 1 cm per day. The majority of the displacement in the region is currently attributed to inflow under Svartsengi with a smaller portion flowing into the magmatic intrusion. In other words, the deformation measured and modeled at Svartsengi is now much greater than that seen near the magma intrusion, but all deformation signals are slowly diminishing. Observed signs of inflow into the magmatic intrusion is now limited to the area east of Sýlingarfell. Despite the slowing down of seismic activity and deformation, an eruption is still considered to be possible. If an eruption does occur, the location thought to be most likely is east of Sýlingarfell.

Seng-29-nov

Here is a timeline for the GPS station Svartsengi (SENG). It shows movements over the last 90 days in the north, east, and vertical directions. The blue line marks the magma intrusion from November 10th until today.

SENG-29-nov-fra-10-nov

This image depicts the movements from the station since November 10th until today.

Updated 27. November at 16:30 UTC

Seismic activity has been relatively stable for the past few days with a daily rate of about 500 earthquakes in the area of the magmatic dike. Most of the seismicity continues to be nearby Sýlingarfell and Hagafell. Around midnight a short-lived seismic swarm commenced in the vicinity of Sýlingarfell and lasted for roughly one hour. A total of 170 earthquakes were detected in the area at a depth of 3-5 km. The earthquakes were almost all very small with one M3.0.

Data from GPS stations and satellite images show that uplift continues in the area of Svartsengi and deformation is still ongoing along and around the dike. The elevated seismic activity which occurred around midnight isn´t associated with any changes to the ongoing deformation. Both seismic and deformation data suggest that magma continues to accumulate beneath Svartsengi and to flow into the middle portion of the dike which formed on 10 November. The seismic swarm that occurred this night might indicate increasing pressure within the dike.

In light of the available data and the newest analysis, an eruption along the dike is still considered likely as long as the magma inflow continues. It is assessed that the area with the highest likelihood for an eruption is in the middle part of the dike between Hagafell and Sýlingarfell. The hazard map published by the IMO on 22 November remains valid.

Additional geodetical modelling has been performed to reconstruct the evolution of the dike which formed on 10 November. These newest results suggest that the dike at depth could be wider than  initially assessed. The time needed to solidify the magma that intruded into the dike would be therefore estimated to be on the order of a few months.

Yfirfarnir-skjalftar-27-nov

This picture shows reviewed earthquakes since 24. November.

Updated 24. November at 13:30 UTC

Yesterday, around 650 earthquakes were measured near the dike intrusion north of Grindavík, and since midnight today, nearly 300 earthquakes have been detected. Most of the earthquakes are below M1.0, but the largest earthquake in the last two days was M2.7 near Hagafell. The seismic activity continues to decrease.

Data from GPS measurements show that deformation continues near Svartsengi, and deformation is still measured around the dike intrusion. However, there are indications that the rate of deformation has decreased based on data from the past week. Though, the interpretation of deformation data is complex at this stage. This is because other processes, such as fault movements related to earthquakes and the viscoelastic response of the Earth’s crust to unrest in the area, have an impact on the deformation signals.

Considering the latest interpretation of all data, the likelihood of a volcanic eruption at some location along the length of the magma intrusion persists. It is possible that magma could emerge in the area between Hagafell and Sýlingarfell. However, as crustal relaxation continues to occur and seismicity decreases, along with a decrease in magma inflow to the intrusion, the likelihood of an imminent volcanic eruption diminishes with time.

Graf-25.-november

Overview of seismic activity from Friday, November 17th. The upper graph shows the number of earthquakes per hour, and the lower graph shows the number of earthquakes per day. The effects of strong wind and heavy sea swell on the Reykjanes Peninsula on November 21st and 22nd are evident in fewer recorded earthquakes due to reduced sensitivity of the seismic network during that time.


Updated 23. November at 12:30 UTC

On 21 November, approximately 300 earthquakes were detected in the region of the magma intrusion. From midnight on 22 November to 18:00 UTC on the same day, around 100 earthquakes had been recorded in the same region, which is considerably less than in recent days. Additionally, the intensity of earthquakes above magnitude 2.0 has decreased. During the period of severe weather on 21 and 22 November, efforts were made to assess how weather conditions and ocean swell influences IMO’s monitoring systems.

Magma inflow rates and crustal adjustments related to the formation of the intrusion continue to diminish. Additionally, crustal uplift near to Svartsengi continues at a similar pace. Geodetical models based on data from 21 November suggest that the influx into the intrusion is greatest near to the Sundhnúkur crater row, about 4 km northeast of Grindavík. Minor surface displacements have been detected within the graben region in and around Grindavík.

The likelihood of a volcanic eruption at some location along the length of the magma intrusion persists. It is possible that magma could emerge in the area between Hagafell and Sýlingarfell. However, as crustal relaxation continues to occur and seismicity decreases, along with a decrease in magma inflow to the intrusion, the likelihood of an imminent volcanic eruption diminishes with time.

Based on the latest data, and considering the evolution of activity since 10 November, the likelihood of a sudden eruption within the Grindavík urban area is decreasing daily, and it is presently assessed as low. It can be assumed that newly emplaced magma beneath Grindavík has solidified partially, thereby reducing the likelihood that the magma will reach the surface within the city limits. However, we emphasise that the possibility of a volcanic eruption at some point along the length of the intrusion, particularly between Hagafell and Sýlingarfell, remains plausible.

It is apparent that there is a strong connection between crustal uplift in the Svartsengi region and the sudden, initial propagation of the magma intrusion on 10 November. Models indicate that the magma in the reservoir beneath Svartsengi may have flowed eastward towards the Sundhnúkur craters, subsequently forming the 15-km-long volcanic intrusion. While crustal uplift in Svartsengi continues, it is expected that the accumulating magma may flow again eastwards, potentially reactivating the intrusion. It is also feasible that a magma intrusion could form to the west of the magma body accumulating beneath Svartsengi. Precursors to such an event would include pronounced seismicity and rapid ground displacements, both of which are monitored closely by IMO continuously.


Updated 21. November at 15:30 UTC

 

Since midnight today, 165 earthquakes have been recorded due to the ongoing volcanic unrest, all below magnitude 2.0 in size. The level of seismicity today is considerably lower than in the recent days, when 1,500-1,800 earthquakes were recorded each day. It can be expected that the intense weather affecting the country has an impact on the sensitivity of the seismic monitoring system to detect the smallest earthquakes, making it difficult to assess whether the seismic activity is decreasing overall.

The deformation associated with the magma intrusion that formed on November 10 continues. Likewise, crustal uplift continues near Svartsengi. The speed of the uplift at Svartsengi has remained almost the same during the past 24 hours.

In collaboration with specialists from the University of Iceland, IMO continues to monitor the area as effectively as possible, constantly re-evaluating and interpreting the data received.

As mentioned before, IMO has increased surveillance in and around Grindavík and the area around Hagafell. The effectiveness of this surveillance depends on the high sensitivity of earthquake and real-time GPS measurements, which are highly dependent on weather conditions. Given the weather forecast for the next two days, which indicates precipitation and significant wind, it can be expected that both seismic monitoring and real-time GPS observations will be affected. Ocean waves also create microseisms that overwhelm the low-frequency detection capabilities of seismometers on the Reykjanes Peninsula. Fog and hail showers could also affect the visual confirmation of an eruption, adding to the monitoring and assessment uncertainty.

 

Updated 20. November at 13:20 UTC

Since midnight today, over 700 earthquakes have been detected in the region of the magma intrusion, the largest of which was magnitude 2.7 near to Hagafell. 

In recent days, between 1,500 and 1,800 daily earthquakes have been measured in the region, with the largest event registering magnitude 3.0 last Friday (17 November). Based on radar imagery from 18 and 19 November 2023, the latest interferogram of the magma intrusion and the surrounding area shows significant crustal uplift in the vicinity of Svartsengi. The newly processed interferogram was reviewed by experts during the weekend (18 – 19 November) from the Icelandic Meteorological Office, the University of Iceland, and the Department of Civil Protection and Emergency Management. The results were also discussed in today’s status meeting, held at IMO. The rapid, ongoing uplift close to Svartsengi is occurring in the same area where uplift was measured before the magma intrusion formed on November 10. Geodetic models derived from satellite images show that the uplift in Svartsengi area is considerably faster than before. Generally, when a magma intrusion forms, subsidence occurs above the centreline of the intrusion, as seen in Grindavík, with signs of land uplift discernible adjacent to the intrusion. Crustal uplift in the Svartsengi region due to magma accumulating at depth has been measurable since the intrusion began to form on 10 November. Initially, the uplift sign was influenced by the formation of the intrusion, but now the dominance of deep magma recharge is apparent.

The clear sign of crustal uplift in Svartsengi region does not change the likelihood of an eruption from the magma intrusion. This is assessed, amongst other things, on the fact that the Earth’s crust over the magma intrusion is much weaker than the crust over the uplift region close to Svartsengi. As long as there is not significant seismicity in the Svartsengi region, there is not a high likelihood of an eruption at that location. Moreover, an eruption is still deemed more likely from the intrusion, particularly if there is a sudden, large inflow of magma into the intrusion.

Our monitoring and hazard assessment preparations are still based on the assumption that the situation could change suddenly with little warning. The Icelandic Meteorological Office, in close cooperation with experts from the University of Iceland, will continue to monitor the area closely, with the goal of continually interpreting and evaluating all available monitoring observations.

20-nov-vincent

COSMO-Skymed interferogram spanning 24-hours between 18−19 November at 06:41. The broad uplift signal visible in orange/red around Svartsengi is indicative of a deep inflation (>5 km) taking place.

Updated 18 November at 15:00 UTC

Seismicity related to the magma intrusion that formed suddenly a week ago remains high and constant. Approximately 1,700 earthquakes have been recorded in the last 24 hours, 1.000 of those recorded since midnight. The largest earthquake during the last 24 hours had a magnitude of 2.8 and occurred near Hagafell, 3.5 km NNE of Grindavík.


Updated 17 November at 12:00 UTC

Seismicity related to the magma intrusion that formed suddenly a week ago remains high and constant, although the level of activity is substantially lower than 10 – 12 November 2023. Approximately 2,000 earthquakes have been recorded in the last 24 hours, with most activity in an area north of Hagafell, towards the Sundhnúkar craters. Most of the seismicity is micro-earthquake activity comprising earthquakes under M 1. The largest earthquake during the last 24 hours occurred at 06:35 near Hagefell; it had a magnitude of 3.0.

According to GPS measurements, ground deformation continues but at a decreasing rate. The latest geophysical models based on GPS data and satellite imagery indicate that the largest movements in the magma intrusion are occurring north of Grindavík, near Hagafell. If magma manages to reach the surface, Hagafell is thought to be a prime location for an eruption.

Subsidence over the magma intrusion remains active, although measurements show a slight slowdown from day to day. Presently, GPS stations located in and around Grindavík, near the center of the subsidence zone, show about 3–4 cm of subsidence per day.

Based on the interpretation of the latest data and model results, a volcanic eruption remains likely, with the highest likelihood of it starting north of Grindavík near Hagafell.

Grindavik_situation_map_20231116_DA

A map showing the extent of the subsidence over the magma instrusion in and around Grindavík. A GPS station (GRIC) located near the center of the subsidence has recorded a total subsidence of 25 cm since the beginning of the event.

 


Updated 16 November at 17:50 UTC

Over the past few days, seismicity near the magma intrusion has remained relatively stable. As of 17:00 today, about 1,400 earthquakes have been recorded since midnight, the largest being 2.9 in magnitude, sourced near Hagafell just after 13:00. Most of the earthquakes were under magnitude 2, with the highest concentration of activity near Hagafell.

Deformation related to the magma intrusion continues to be measured, although it has slowed slightly since yesterday. The latest models, derived from GPS measurements and satellite data, still suggest that the largest movements of the magma intrusion are north of Grindavík near Hagafell. If magma manages to break through to the surface, it is most likely to happen in the region of Hagafell.

Eartly today, sulphur dioxide (SO2), a type of volcanic gas, was measured from a borehole at Svartsengi, located just north of Þorbjörn. The borehole extends eastward to considerable depth towards the Sundhnúkur crater row. The base of the borehole therefore reaches close to the location in the crust was the magma intrusion is located. Further gas measurements will be conducted tomorrow, 17 November. The detection of volcanic gas from such a borehole is another independent confirmation of the presence of magma north of Hagafell, as indicated by seismic activity and geophysical modelling results.

The likelihood of an eruption remains high. Monitoring continues for signs of shallowing seismicity and sudden crustal movements, which could be precursors to magma breaking its way to the surface. At the time of writing, no such signs had been observed.


Updated 15. November at 11:30 UTC

Since midnight, about 800 earthquakes have been measured, most of them in the middle of the magma dyke at Sundhnúk at a depth of about 3-5 km. Seismic activity has remained constant since 11th of November. The main monitoring focus on seismic activity remains in the area of ​​the dike and Grindavík.

Deformation measurements show continued deformation in the area. They are consistent with magma still flowing into the dyke. Part of the magma dyke seems to be solidifying, especially at the edges, but not at the magma inflow area, which is believed to be near Sundhnúk.

Measurements of sulfur dioxide (SO2) seem to show fluctuating degassing due to the magma dyke, but further measurements are needed for confirmation. Analysis of this data is currently underway in collaboration with the Chalmers University in Sweden.

The fiber optic cable of HS Orka, that runs from Svartsengi west of Þorbjörn to Arfadalsvík is beeing used as a continuous seismic measuring line with high sensitivity. This is a new technology that has developed in recent years and is now used as additional measurements in collaboration with HS Orku and ETH in Switzerland.

Overall, the situation seems to be unchanged since yesterday. The probability of an eruption is still considered high. In the event of an eruption, the most likely location is at the magma dyke.


Updated 14. November at 19:20 UTC

Earlier this week, IMO specialists installed two DOAS remote sensing instruments on Húsafell. These instruments can measure the presence and the amount of SO2 in the atmosphere. One of the DOAS instruments detected SO2 yesterday and today at the newly formed graben, located between Sundhnúkagígar and Grindavík. Because of the low amount of daylight, the measurements can be imprecise, and it took time to review the data and interpret it. In the last two days, eastern winds have been prevalent in the area, so it cannot be ruled out that recent strong seismicity has caused the release of SO2 from beneath Fagardalsfjall, as magma at that location has not solidified yet since the eruption in July 2023.

It is hard to estimate the depth from which the SO2 is being released as the process is influenced by magma pressure. However, it is thought that the magma needs to be in the upper hundred meters of the crust in order for SO2 to be released. This is one of the reasons why the DOAS instruments have been sited close to Grindavík.

DOAS (Differential Optical Absorption Spectrometer) is a tool that can detect sulfur dioxide in the atmosphere. The method relies on visible light, which travels through the atmosphere, hits a sensor in the measuring device, which is then analyzed for certain colors (wavelengths) that are missing from the spectrum. Sulfur dioxide absorbs certain wavelengths of light, which means that light hits the measuring instrument in a different way if SO2 is detected. The probe scans certain sectors of the sky, and it provides information on the concentration of sulfur dioxide within the area scanned. DOAS measurements need daylight to work, so operating such instruments in the wintertime in Iceland can be challenging.


Updated 14. November at 12:40 UTC

Since midnight, 14 November, over 700 earthquakes have been located along the orientation of the magma intrusion, the largest of which was M 3.1 near to Hagafell. Last night, 13 November, stress-triggered seismicity occurred close to Kleifarvatn, with the largest earthquake registering M 3.8 at 21:09 UTC. Today, most earthquakes are occurring along the magma intrusion, with the majority being micro-earthquakes, commonly at focal depths of 3 to 5 km.

Deformation measurements, including high-resolution aerial observations, satellite radar imagery, and ground-based GPS observations reveal continued, ongoing ground movements due to the ongoing formation of the magma intrusion. These results are consistent with continued, albeit much lower magma inflow to the region of the intrusion.

Between 12 and 13 November, the inflow is estimated at 75 m3 / s, and the average depth to the top of the magma intrusion is thought to be around 800 m. The inflow and depth estimates are derived from model-based calculations, and they are subject to uncertainty.

Throughout this period of volcanic unrest, the focus has been continuous monitoring of seismicity and ground deformation in the Grindavík – Svartsengi region. To further our monitoring capabilities, we have installed additional GPS stations in and around Grindavík. The latest measurements from these stations show that the graben-like formation is still forming and mechanically active. Furthermore, to increase our ability to warn of an eruption, we have installed ground-based SO2 detectors that overlook Grindavík and south of Sundhnúkur.

In summary, the likelihood of an eruption remains high. If an eruption occurs, the most likely location with be along the orientation of the magma intrusion, beginning as a fissure eruption.


Updated 13. November at 16:20 UTC

 

Seismicity along the magma intrusion continues, although the size and intensity of the activity is decreasing. Since midnight today, 13 November, around 900 earthquakes have been detected. The seismic activity is concentrated on the region of the intrusion, between Sundhnúkur and Grindavík at a depth of about 2–5 km.

Decreasing rates of ground deformation are seen in GPS data from Grindavík. Satellite radar results show a graben-like formation that cuts through part of Grindavík. This feature was first identified by IMO in satellite radar imagery early on 11 November.

Bylgjuvixlm-13-nov-michelle

 

This ascending COSMO-SkyMed (CSK) interferogram covers the time period 3-11 November and shows an extensive deformation field related to the dike intrusion that began on the afternoon of the 10 November within the Reykjanes-Svartsengi volcanic system. This CSK interferogram and the previous (spanning 2-10 November) supported the difficult decision made by Civil Protection to evacuate the town of Grindavík late Friday evening. It also enabled modelling of the dimensions of the dike intrusion (on the 11 November), which provided a median dike length of 15 km and top depth of less than 1 km below the surface. The imagery shows over 1-m of ground displacement in the western part of Grindavík, caused by the propagation of the magma intrusion. From geodetical modelling results, we infer that (as of 12 November) the greatest area of magma upwelling is sourced close to Sundhnúkur, 3.5 km north-northeast of Grindavík.

New geodetic modelling is currently being undertaken, using an ICEYE interferogram and GNSS observations spanning the last 24-hours, to better assess the ongoing activity and provide an estimate of the current magma inflow rates.

According to our latest estimates, the volcanic hazard assessment in and around Grindavík is unchanged from 12 November. All monitoring systems are being monitored closely in real-time, especially near Grindavík, for any indications of sudden change. The natural hazards monitoring team at IMO is operating at maximum surveillance while the Department of Civil Protection and Emergency Management coordinates short-term, temporary access to Grindavík today, 13 November.

13-nov-enska-blar-litur

Estimate of the vertical displacements caused by the dike during its initial propagation from Friday afternoon to Saturday morning. The displacements were estimated by combining ICEYE and COSMO-SkyMed pixel offset tracking results.


Updated 12. November at 12:30 UTC

 

Since the morning of November 11th, seismic activity related to the magma intrusion remains fairly constant. Since midnight November 12th, around 1000 earthquakes have been recorded within the dyke, and all of them have been below M3.0 in magnitude. The most seismic activity has been located in the region north of Grindavík. Most of the earthquakes are at a depth of 3-5 km corresponding to the lower part of the dyke intrusion.

GPS measurements covering the past 24 hours show that deformation associated with the dyke intrusion that formed on Friday, November 10th has slowed. This can be an indication that magma is moving closer to the surface, new models will be run as soon as new data comes in to update the model.

It was a joint assessment from the meeting, based on the latest data, that there is scope for temporary measures under the control of the Department of Civil Protection and Emergency Management to collect necessities for the residents and attend to urgent errands in Grindavík and the surrounding area. During such operations, it is necessary to increase the vigilance of the area through additional monitoring with the aim of improving the detection of magma reaching the surface. It was the opinion of the scientists that it would be advisable to start these operations immediately, as uncertainty about the progress of the event grows as the day progresses. The final decision on whether these actions will be taken, and their implementation is in the hands of public safety and the Police Chief in Suðurnes.

In light of this joint assessment has the Police Chief in Suðurnes decided to allow inhabitant to part of restricted area in Þorkötlustaðahverfi and it is only to retrieve vital items, pets and livestock. This will be organised and controlled operation by the Police. This permission only applies to Þorkötlustaðahverfi. Note, special operation is ongoing to pick up all horses in the area north of Austurver.  

 

 

This news has been updated since the latest information from the Police Chief in Suðurnes.

Updated 11. November at 18:30 UTC

At 18:00 today, 11 November, a status meeting concluded between scientists at the Icelandic Meteorological Office, the University of Iceland, and the Department of Civil Protection and Emergency Management. The purpose of the meeting was to discuss the latest measurements of seismicity and ground deformation in the region of Grindavík, in addition to reviewing the latest geophysical models and hazard assessments. From combined assessments of satellite radar imagery, ground-based GPS measurements, and seismicity, it was concluded that the ongoing dike intrusion represents a serious volcanic hazard. 

From geophysical models of the dike intrusion, it is estimated that the intrusion is propagating upwards slowly, with magma thought to be 800 m beneath the surface. The exact location of a possible eruption site is unknown, but the 15-km length and orientation of the dike gives a good indication of possible sources. The overall assessment from the status meeting was that the likelihood of a volcanic eruption is high, and that an eruption could be possible on a timescale of just days. Based on the extent of the dike, magma could emerge from its southern, just outside of Grindavik. Therefore, the likelihood of a submarine eruption has also increased, so preparations must be made for the possibility of explosive activity. A hazard area has been defined based on the location of the dike, as shown in the map.

Kort-ragnar-enska-11-nov

Status map showing the location of the dike intrusion based on combined satellite radar imagery, GPS measurements, and geophysical modelling.

Updated 11. November at 12:00pm

 

Since midnight, around 800 earthquakes have been measured in the region where the magma intrusion is occurring. The earthquake activity has diminished slightly in the past hours, but it remains high. Most of the recent earthquakes have occurred close to Grindavík, where the southwest end of the magmatic dyke is estimated to be located.

Analysis of the earthquakes from today and yesterday is ongoing. The goal of this work is to better understand the evolution of the magma intrusion. Presently, the data indicates that the magma intrusion extends from Stóra-Skógsfell in the north to Grindavík in the south, where it extends beneath the sea. In accordance with the latest preliminary models, using the most recent satellite data acquired last night, the shallowest depth of the top of the magma intrusion north of Grindavík is 1.5 km. Joint interpretation of the ground and satellite measurements indicate that the size of the magma intrusion and the rate at which it is moving are several times larger than have been measured previously on the Reykjanes Peninsula. Our assessment is that an eruption, if it were to occur, will originate from the northern side of the magma intrusion. This means that there is a greater likelihood of an eruption beginning close to Sundhnjúkagígur.

Scientists are meeting regularly to interpret the data and update the latest models and hazard assessments. A meeting for journalists will be held at 12:00 at the Department of Civil Protection and Emergency Management. The current conditions and future scenarios will be discussed.

The likelihood of a volcanic eruption occurring in the near future is deemed considerable.

 

Skjalftavirkni_1011_1111

Reviewed earthquakes since 9pm last night.

Updated 10. November at 11:30pm

 

Significant changes have occurred in the seismic activity measured near Sundhnjúkagígar north of Grindavík and deformation observed in the Reykjanes Peninsula this afternoon. The seismic activity has moved south towards Grindavík. Based on how the seismic activity has evolved since 6 PM today, along with results from GPS measurements, there is a likelihood that a magma intrusion has extended beneath Grindavík. In light of this outcome, the police chief in Suðurnes, in cooperation with the Civil Protection Authorities, has decided to evacuate Grindavík. An emergency level of civil protection is now in effect. This is not an emergency evacuation. Residents of Grindavík are advised to proceed with caution.

At this stage, it is not possible to determine exactly whether and where magma might reach the surface. There are indications that a considerable amount of magma is moving in an area extending from Sundhnjúkagígum in the north towards Grindavík. The amount of magma involved is significantly more than what was observed in the largest magma intrusions associated with the eruptions at Fagradalsfjall. Further data is being collected to calculate models that provide a more accurate picture of the magma intrusion. It is currently not possible to say when this work will be completed.


 

Updated 10. November at 8pm

 

The seismic activity currently measured at Sundhnjúkagígar occurs within an area about 3 km northeast of Grindavík. The shallowest earthquakes measured now are at a depth of about 3-3.5 km.

The signs that can be seen now at Sundhnjúkagígar are similar to those seen on the eve of the first eruption at Fagradalsfjall in 2021 and are very similar to the seismic activity that was measured about a month before that eruption. The most likely scenario now, taking into account the activity that culminated in the onset of the March 19th 2021, is that it will take several days (rather than hours) for magma to reach the surface.  

Samsett-mynd-10-nov

 

Earthquakes on the 10th of November (until 6:48pm). The Icelandic Meteorological Office’s seismic network is shown with triangles. Four seismic stations surrounding the current seismic activity have been showing a large increase in tremor since 3pm.

Updated 10. November at 6:30pm

 

The National Commissioner of the Icelandic Police, in consultation with the Police Commissioner of Suðurnes, has declared a Civil Protection Alert Phase due to the intense earthquake swarm that commenced 3pm today at Sundhnjúkagígar, north of Grindavík. There is the possibility for larger earthquakes than have been experienced thus far, and this sequence of events could lead to an eruption. The Civil Protection Alert Phase means that the risk is increasing, and measures are being taken to ensure the utmost safety of those who live/stay in the area. This is done by increasing precautions in the relevant area.

The Aviation Color Code has been elevated to orange (heightened unrest with increased likelihood of eruption). IMO is closely monitoring the situation. Residents are encouraged to follow the information provided on Almannavarnir.


 

Updated 10. November at 2pm

 

Earlier today, at 12:44, an earthquake of magnitude 4.1 occurred near Sýlingarfell, west of Sundhnjúkagígar. The craters are about 2-3 km northeast of Grindavík. A dense swarm of earthquakes began around 07:00 this morning in the same area, and nearly 800 quakes have been recorded since midnight, including 9 greater than magnitude 3. The depth of the earthquakes is about 5 km. Such earthquake swarms have previously been recorded in this area. It cannot be ruled out that the seismic activity near Sundhnjúkagígar is due to magma movements at depth.

Magma accumulation continues near Þorbjörn at the same depth and at a similar rate as before. It is accompanied by swarm-like seismic activity, as was noticed yesterday and this morning. While magma accumulation continues, ongoing seismic activity can be expected due to stress release in the area. Earthquakes up to magnitude M5.5 can be expected in such swarms, and the seismic activity may shift between areas. At this stage, there are no indications that magma is forcing its way to the surface.

Yfirfarnir-skjalftar-10-nov

 

Reviewed earthquakes since midnight

Updated 9. November at 12:20pm

 

Around 1400 earthquakes have been recorded in the last 24 hours. Seismic activity increased from midnight, and the SIL seismic network has detected seven earthquakes above M4.0 since then. The largest earthquake measured M4.8 at 12:46am. It was located west of Þorbjörn. It is the largest earthquake since the activity began on October 25th. Seven earthquakes M4.0 or larger in size were measured in the area from Eldvörp to the area east of Sýlingarfell. While the accumulation of magma continues, seismic activity can be expected on the Reykjavík Peninsula because the magma intrusion causes increased tension in the area.

According to GPS data at midnight, uplift continues in the area. The GPS data is being reviewed in relation to the seismic activity tonight. Since the beginning of the inflation until today, the uplift has been fairly even, although an acceleration of the process has been observed between days. The seismic activity last night and this morning is an example of this episodic seismic activity that can be expected while magma accumulation is in progress. The fact that there are now larger earthquakes than before in the area does not necessarily mean an increased rate of magma accumulation.

9-nov-mynd

 

Reviewed earthquakes since midnight last night

Updated 8. November at 2:40pm

 

Approximately 1200 earthquakes have been measured in the last 24 hours, most of them in the area between Þorbjörn and Sýlingafell, similar to the day before. The largest earthquake was M3.4 at 12:31am last night, just south of Þorbjörn. The seismic activity continues at the same depth as before. It is likely that seismic activity will continue, and be episodic in intensity, while magma accumulation is ongoing. 

Uplift continues at a similar rate as before according to Satellite and GNSS data. Interferogram (InSAR) for the period 28th of October – 6th of November showing near-vertical motion confirms this, but it also shows offsets due to fault movements associated with the seismic activity. Updated models based on the same data estimate that magma continues to accumulate in a horizontal sill at a depth of about 5 km and since the beginning of the inflation event (October 27th) the average inflow is estimated about 5 m3/s (uncertainty is ±2 m3/s)

Bylgjuvixlm-8-nov-uppfaerd

 

Interferogram (InSAR) for the period 28th of October – 6th of November shows that deformation in that period is around 7 cm. SW of Mt. Þorbjörn is an offset in the deformation signal caused by fault movements by earthquakes.

Updated 7. November at 1:30pm

 

There have been around 900 earthquakes in the last 24 hours, most of them in the area between Þorbjörn and Sýlingafell. The largest earthquake was M2.9 and occurred around 7 am this morning. The seismic activity remains at the same depth as before.

According to satellite data processed around 5 pm yesterday and covers the period between November 4-6, confirms that uplift continues around Þorbjörn. The same data shows no signs of magma accumulation in Eldvörp or near Sýlingarfell, east of Svartsengi where seismic activity has been measued in recent days.

Magma accumulation continues at a depth of around 5 km in the are NW of Þorbjörn. If October 27th is considered the starting day of the inflation event until today, the rate of uplift has been fairly constant, although an acceleration of the process has been observed between days. It is likely that seismic activity will continue, and be episodic in intensity, while magma accumulation is ongoing.  

Yfirfarnir-skjalftar-7-nov

 

Reviewed earthquake locations since 6th of November and today until noon.

Updated 6. November at 1:15pm

 

In the last 24 hours around 1300 earthquakes have been detected on the Reykjanes peninsula, of which three earthquakes were above M3. The largest earthquake was M3.6 this morning and located 3 km NE of Mt. Þorbjörn.

Deformation data shows that uplift continues in the area and there are indications on GNSS observations of an increase in inflation rates since 3rd of November. Since the start of the inflation, the uplift at the GNSS station at Mt. Þorbjörn has reached 7 cm. The deformation is caused by a sill-type intrusion at around 5 km depth. Modelling, based on data since 27th of October, indicates that the volume change associated with this inflation event has reached almost two times the volume change associated with the four previous inflation events in the same area between 2020-2022. Inflow of magma/magmatic fluids into the sill-type body is estimated at approximately 7 m3/s which is about four times greater than the highest inflow estimated during previous inflation events here.

While the inflation  continues, increased seismicity in the area can be expected from additional stress changes  induced within the crust. 

6-nov-2023

Data from GNSS station at Mt. Þorbjörn. The graph at the bottom shows the uplift.

 

Updated 4. November at 11:30pm

 

After 17:30 yesterday, seismic activity decreased considerably. In the last 12 hours, about 900 earthquakes have been detected, all under M3.0. The activity after midnight as mainly been located at Sundhnjúkagígar – NE of Þorbjörn, as well as west of Eldvörp.

Seismicity has decreased considerably since yesterday, but the development of earthquake magnitudes, number of earthquakes and their location is comparable to the development previously seen related to magma accumulation in the vicinity of Þorbjörn.

The latest deformation data shows that uplift continues in the area. This uplift is thought to be due to magma accumulation NW of Þorbjörn at 4-5 km depth. While that magma accumulation continues, increased seismicity in the area can be expected from increased stresses in the crust. Rockfall can occur following large earthquakes, so caution should be taken by steep slopes.

The Icelandic Meteorological Office continues to monitor the area closely and to meet with the Civil protection agency to discuss the situation. Signs of magma coming towards the surface would appear as increased, shallower seismicity and rapid crustal deformation at the surface as well as volcanic tremor, which is a high rate of many small earthquakes. At the moment no clear signs can be seen of any of this, but the situation can change on short notice.

Virkni_04112023

Earthquakes (circles) with magnitude over 1.5, from midnight on 3 November until 10:45 on the 4 November. The colour bar to the left shows the time of the earthquakes and the size of the circles represents the relative size of the events. Locations of seismic stations (triangles) and GPS deformation stations (squares) are also shown.


 

Updated 3. November at 3pm

An earthquake of magnitude 4.3 was detected at 1:14 pm, today between Þorbjörn and Sýlingarfell. Another earthquake of magnitude 3.5 was detected at 2:01 pm in Þorbjörn. These earthquakes are thought to be due to continuing stress in the crust from magma accumulation undir Þorbjörn mountain. No volcanic tremor has been detected and the area is still being closely monitored.

Updated 3. November at 1:50pm

 

According to measurements from 11:00 am today, the uplift centered northwest of Þorbjörn continues. The uplift is caused by a magma intrusion at a depth of about 4 km. Seismic activity continues on the Reykjanes peninsula due to crustal stress changes caused by the intrusion. An increase in earthquake activity was detected after midnight and into the morning. Since midnight, around 1.000 earthquakes have been recorded in the area, with two being above M3.0 and two above M4.0. The biggest earthquake of the current swarm was measured at 8:06 am and was 4.3 in size. The biggest earthquakes last night seem to line up in a north-south direction west of Þorbjörn. This is happening on previously known fissures, where tension has been accumulating associated with plate tectonics and may curl due to tension from intrusions.

There are currently no clear signs of magma moving closer to the surface. Signs that magma is making its way to the surface would appear in shallower seismic activity and increasing tremor, which is a high frequency of small earthquakes. At the same time, sudden deformation of the surface should be measured with GPS measurements. The development of this event is closely monitored, as the course of events can change with very little notice.   

Model calculations show that the intrusion is located northwest of Þorbjörn, as shown in the accompanying image.  The most recent seismic activity has been over the intrusion itself. The earthquakes measured at Eldvörp and east of Grindavík road are due to tension from the magma intrusion by Þorbjörn, rather than signs of magma movements in those areas.

Ragnar-enska-3-nov

 

 

Approximate center of magma intrusion according to model calculations based on GPS and satellite images together with seismic activity from November 2nd at 8pm to November 3rd at 12pm larger that M1.0 in size. The model assumes a box-shaped intrusion, but its length and width are subject to quite a bit of uncertainty. The model will be frequently updated with the newest data once aquired, and the size and shape of the intrusion might change considerably, so there is quite some uncertainty to the model.


 

Updated 2. November at 3pm

 

GPS data from the last 24 hours indicate that uplift continues at a similar rate in the area northwest of Mt. Þorbjörn. Earthquake activity has been quite stable, but yesterday around 800 earthquakes were recorded in the area around Þorbjörn, and the largest was M3.7 at 12:56 am. Since midnight today, around 400 earthquakes have been recorded in the area, the largest measuring M2.8 at 9:51 am. More detailed analysis of recent GPS data confirms that a magma intrusion is forming at a depth of 4-5 km under the area northwest of Þorbjörn.  

It is important to note that seismic activity is will likely continue northwest of Þorbjörn, and earthquakes over M4.0 could be found in populated areas. Triggered seismic activity can also be expected in the coming days because the magma intrusion causes increased tension in the area. Rockfall can occur following strong earthquakes, so it is important to be cautious on steep slopes.  

2-nov

 

Reviewed earthquakes from midnight November 1st until noon November 2nd.

Updated 1. November at 12:20pm

 

On 25 October, an intense earthquake swarm began near Svartsengi, north of Grindavík on the Reykjanes Peninsula. So far, over 10,500 earthquakes have been detected in the swarm, with over 26 earthquakes exceeding magnitude three, the largest of which was magnitude 4.5 on 25 October at 08:18 UTC.

The latest satellite radar image, acquired late on 31 October, reveals 5 to 6 cm of ground movements over 12 days, centered just northwest of Mt. Þorbjörn. The same displacement signal is seen in continuous GPS measurements from stations in the region, beginning on 27 October. The latest GPS results from 1 November indicate that ground displacements continue in the region. Combining seismic, geodetic, and satellite-based observations, we infer that a volcanic intrusion is located at about 4 km depth just northwest of Mt. Þorbjörn. Presently, there are no indications that the volcanic intrusion is becoming shallower. We expect that seismicity will continue northwest of Mt. Þorbjörn, and this could include felt earthquakes exceeding magnitude four. Triggered earthquake activity is also possible in the coming days due to stress increases caused by the intrusion. This is a likely explanation for the ongoing seismic activity detected west of Þorbjörn in Eldvörp on 1 November. Triggered seismicity is also possible due to the long-term effects of magma accumulation beneath Fagradalsfjall.

Satellitbaseret InSAR-billede af Reykjanes-halvøen, der strækker sig fra 19. til 31. oktober. Dette billede giver et indblik i jordens deformation i løbet af de sidste 12 dage. Det største deformationssignal er centreret nordvest for bjerget Þorbjörn. Fra GPS-målinger er det tydeligt, at størstedelen af ​​centimeterskalaen jordforskydning er sket siden 27. oktober.

 

Opdateret 31. oktober kl. 17.00

 

I morges kl. 8.40 begyndte en jordskælvsværm ved Þorbjörn, som varede i næsten 2 timer og var usædvanlig intens. Det største jordskælv i sværmen målte M3,7. Aktivitetens centrum var lige øst for midten af ​​den stigning, der er observeret de seneste dage. Jordskælvenes dybde blev anslået til mellem 5 og 1,5 km dybde. Jordskælvsværmen er et tydeligt tegn på magmabevægelser i dybden. GPS-målinger understøtter fortolkningen, selvom stigningen, der startede for omkring fire dage siden, er aftaget. Tidligere i dag var der et møde med civilforsvaret og interessenter på Reykjanes-halvøen, hvor de seneste målinger og mulige scenarier og svar på det aktuelle scenarie blev diskuteret.

Situationen overvåges nøje

IMO følger udviklingen nøje og ser på, om mikroseismisk aktivitet stiger tættere på overfladen, hvilket kan være et tegn på, at magma bryder sig vej gennem jordskorpen. I øjeblikket er der ingen tegn på, at jordskælvsaktiviteten bliver mere lavvandet. Situationen kan dog hurtigt ændre sig, og det er ikke muligt at udelukke et scenarie, der involverer et lavaproducerende udbrud i området nordvest for Þorbjörn. Det er vigtigt at påpege, at magmabevægelser, svarende til dem, der observeres tæt på Þorbjörn, ofte forsvinder og ikke fører til et vulkanudbrud. Ikke desto mindre kunne langvarig riftning og øget (udløst) jordskælvsaktivitet i Svartsengi-området have skabt svagheder i skorpen, hvilket gør det lettere for magma at bevæge sig til lavere dybder.

THob_Skjalftavirkni_31102023

 

Gennemgået jordskælv fra midnat i dag.

Opdateret 30. oktober kl. 11.30

 

 

Sentinel-satellitdataene, der forventes at blive modtaget i går, er ikke ankommet endnu, men cGPS-dataene i området omkring Svartensgi og Þorbjörn viser, at deformationen stadig er i gang. Deformationshastigheden siden begyndelsen af ​​denne påtrængende begivenhed har været svagt faldende over tid. Foreløbige resultater fra deformationsmodeller tyder på, at den gennemsnitlige dybde, hvor den magmatiske instruktion finder sted, er omkring 4 km.

I løbet af de sidste 24 timer er omkring 1300 jordskælv automatisk blevet registreret på Reykjanes-halvøen. Det meste af denne seismicitet er placeret i en dybde mellem 2-4 km. Det største jordskælv havde en størrelsesorden M2,7 den 29. oktober kl. 11:40 UTC.

Forskere fra det islandske meteorologiske kontor foretager yderligere overflademålinger i området, herunder geokemiske observationer. Der opretholdes regelmæssig kommunikation mellem IMO, HS-Orka og Civilbeskyttelsen, mens denne uro fortsætter.

THOB_8hrap-30-okt

8-timers løsning til cGNSS THOB-stationen i Þorbjörn, der viser det seneste datapunkt opdateret kl. 08:00 UTC i dag


 

Opdateret 29. oktober kl. 14.00

 

De seneste cGPS-deformationsdata omkring Þorbjörn og Svartengi-området bekræfter, at deformationen, som startede 27. oktober, fortsætter. Som indledningsvis anført, er de igangværende deformationshastigheder højere end i tidligere hændelser, som fandt sted i et lignende område i 2020 og 2022. Samlet set har seismiciteten nord for Grindavík været faldende i løbet af det seneste døgn, og der er ingen væsentlige ændringer i jordskælvsdybderne. Det er dog vigtigt at understrege, at den nuværende deformation kan udløse fornyet seismicitet i området, som kunne mærkes af mennesker.

Nye satellitdata forventes at blive leveret senere i dag, og et nyt interferogram vil blive behandlet, så snart dataene er tilgængelige. Resultaterne vil give os mulighed for at identificere og fortolke de deformationsprocesser, der har fundet sted på halvøen i løbet af de seneste 12 dage. Vi forventede at offentliggøre resultaterne i morgen.

En episode med kompleks vulkan-tektonisk uro påvirker i øjeblikket Reykjanes-halvøen. Det fortolkes som et resultat af flere deformationskilder i dybden, som interagerer og påvirker et bredt område på tværs af halvøen.

THOB_8hrap-29-okt

8-timers løsning til cGNSS THOB-stationen i Þorbjörn, der viser det seneste datapunkt opdateret kl. 08:00 UTC i dag, den 29. oktober.

 

Opdateret 28. oktober kl. 13.30

 

De seneste cGPS-målinger, sammen med et nyligt erhvervet InSAR-billede over Reykjanes-halvøen, afslører et tydeligt tegn på jordløft, centreret omkring Svartsengi. Dette løftesignal begyndte på et tidspunkt den 27. oktober, og det afspejler en trykstigning, der sandsynligvis er forårsaget af en magmatisk indtrængen i dybden. Midten af ​​løftesignalet er omkring 1,5 km nordvest for Þorbjörn, tæt på Den Blå Lagune. I 2020 og 2022 blev lignende opløftningssignaler detekteret i samme område og med lignende geometri. Dette er nu den femte inflationsbegivenhed i området. Fra en indledende vurdering forekommer det igangværende opløftningssignal hurtigere end tidligere. I øjeblikket er der ingen indikationer på, at magma bevæger sig på lavere dybde. Situationen kan dog udvikle sig hurtigt. For eksempel er der sket betydelige fraktureringer i Svartsengi-området på grund af udløst seismicitet i de seneste dage. En sådan frakturering kunne gøre det muligt for magma at finde veje til mindre dybde.

Samlet set viser de seneste deformationsresultater fra Reykjanes-halvøen en kompleks, igangværende proces med magmabevægelser i jordskorpen. Disse processer påvirker et bredt område, herunder Fagradalsfjall (hvor langsigtet inflation fortsætter), øst for Festarfjall (hvor deformationen ser ud til at være stoppet), og – i de sidste 24 timer – viser et område tæt på Svartsengi inflation.

Den seismiske sværm, der begyndte den 25. oktober nord for Grindavík, har resulteret i over 7.000 jordskælv. Niveauet af jordskælv er reduceret betydeligt, selvom sværmen stadig er i gang, hvilket betyder, at der stadig er sandsynlighed for jordskælv.

Geophysical modelling is underway today to determine the depth and size of the uplift source close to Svartsengi. An additional satellite radar image will be available from Reykjanes Peninsula on 29 October. This image should provide an even closer insight into the recent magma movements and deformation pattens on the peninsula.

Insar-28-okt-nr-2

 

 

“Line-of-sight” (LOS) deformation measured by the ICEYE SAR satellite between the 26 October at 05:21 UTC and the 28 October at 05:21 UTC. Satellite data provided in collaboration with ICEYE (https://www.iceye.com/).


 

Updated 27th of October at 2pm

 

The ground-deformation signal detected since yesterday in the area East of Festarfjall is confirmed by the latest cGPS data. The horizontal displacement over the past few days is ~ 2 cm as seen at FEFC station and movement has now also been measured at another cGPS station located in Selatangar. A 1-day interferogram spanning 26 to  27 of October, does not reveal any significant changes in the area, but the signal at FEFC measured during this 24-hr period was smaller than 1 cm, likely too small to be detected by this interferogram.  cGPS stations in Grindavík and north of here show no significant changes.

The seismic swarm north of Grindavík continues with around 1000 earthquakes since midnight. A total of 5800 eqs have been recorded since the beginning of the activity. An earthquakes M4.0 was measured at 04:02 UTC on 27 October around 2 km north of Grindavík. The seismic activity is interpreted as the response of the crust to the stress changes induced by continued magmatic inflow at depth beneath the Fagradalsfjall volcanic system.

Gps-stod-27-okt

 

Displacement at cGNSS station FEFC east of Festarfjall. Blue vertical line marks the onset of a dike intrusion in July 2023 and the red line the start an eruption near Litli-Hrútur 10th of July 2023. Most recent data points show up movement and horizontal movement towards SE.

Kort-27-okt

cGNSS stations at Reykjanes Peninsula. Data from stations FEFC and STAN east of Festarfjall show movement in the last day.

Updated: 26th of October at 5pm

 

The seismic swarm that commenced on 24 October continues. Over 4,000 earthquakes have been recorded on the Reykjanes Peninsula, of which 14 had a magnitude exceeding M3. Most of the activity has occurred between Stóra-Skogafell and North-East of Eldvörp. Seismicity is located between 2 and 6 km depth, with the largest earthquake (M4.5) measured on 25 October at 08:18 UTC. Scientists at the Icelandic Meteorological Office (IMO) interpret the ongoing seismic activity as triggered by stress induced by the ongoing deformation at Fagradalsfjall, which began soon after the summer 2023 eruption. The ongoing seismic swarm is expected to continue for the coming days. In the longer-term, the continued accumulation of magma beneath Fagradalsfjall could cause further seismic swarms on the peninsula.

Jorddeformationsmålinger nær Svartsengi og Grindavík viser ingen ændringer relateret til den igangværende seismiske sværm nord for Grindavík. En enkelt GPS-station (FEFC), øst for Festarfjall, begynder at vise lokaliseret bevægelse i sydøstlig retning. Disse målinger kunne indikere tilstedeværelsen af ​​magma i dybden langs fortsættelsen af ​​digeindtrængninger, der er i nordøstlige retning mod sydvest, som er dannet under Fagradalsfjall siden 2021.

Personale fra IMO fortsætter med at overvåge de seismiske uroligheder nøje. I de kommende dage vil satellitdata blive brugt til bedre at vurdere den rumlige udstrækning af enhver jorddeformation. Målingerne vil også blive brugt til bedre at forstå igangværende geofysiske processer på Reykjanes-halvøen.

Kort-a-ensku-26102023

 

Gennemgået udløste jordskælv fra 20.-26. oktober.

Skrevet 25. oktober: 

I nat startede en intens jordskælvsværm nær Svartsengi, nord for Grindavík. Over 1000 jordskælv er blevet opdaget der siden midnat, og sværmen er stadig i gang. De største jordskælv, der er registreret, er M3.9 kl. 5.35 UTC og M4.5 kl. 8.18 UTC. Begge disse jordskælv opstod på omkring 5 km dybde. Seneste deformationsdata indsamlet fra flere stationer omkring Þorbjörn/Grindavík området viser ikke signifikante ændringer korreleret med den igangværende seismiske aktivitet. I lyset af de data, der i øjeblikket er tilgængelige, fortolkes denne seismicitet til at være sandsynligt udløst af stressændringer relateret til tidligere påtrængende aktivitet på halvøen. Der er i øjeblikket ingen indikationer på magmavandring under Þorbjörn/Grindavík-området, men situationen kan ændre sig når som helst, og den kan udvikle sig over kort tid fra timer til dage. Som rapporteret i september er en magmatisk indtrængen i gang under Fagradalsfjall.

 

Personale fra IMO fortsætter med at overvåge området tæt og fortolke de nyeste data, efterhånden som de bliver tilgængelige.

Usikkerhedsniveauet for Department of Civil Protection er blevet erklæret på grund af denne seismiske sværm.

Gps-mynd-fyrir-frett

 

 

8-timers løsning til cGNSS THOB-stationen i Þorbjörn, der viser det seneste datapunkt opdateret kl. 08:00 UTC i dag.

Mynd-3

Gennemgået jordskælvssteder fra midnat til middag den 25. oktober .

 

SjalfvirktAutomatiske lokaliseringer af jordskælv fra midnat til middag den 25. oktober .


ght – Kilde:
 
 
 

Almannavarnir – Civilbeskyttelse/Björn Oddsson

Opløftning ved Svartsengi fortsætter

Magma flyder højst sandsynligt ikke længere ind i diget, der blev dannet den 14. januar, og at udbruddet er afsluttet. En opdateret farevurdering vurderer stadig, at faren for sprækker i Grindavík er høj

19.1.2024

Opdateret 19. januar 16:30 UTC

 

Der registreres stadig tydelige signaler om en fortsat landhævning under Svartsengi. Det er endnu for tidligt at sige, om hastigheden af ​​landhævningen er steget siden før udbruddet den 14. januar. De første målinger tyder på, at det er tilfældet, men som tidligere skrevet kan målinger svinge fra den ene dag til den anden og en længere tidslinje for måling er nødvendig for at kunne fortolke den langsigtede udvikling af landhævningen.

Seismisk aktivitet fortsætter med at falde i området af magmadiget, og deformationssignaler set på GPS-enheder tyder på en betydelig opbremsning af jordens bevægelse sammenlignet med tidligere dage. Disse oplysninger tyder på, at magma ikke længere strømmer ind i diget, og at udbruddet er afsluttet.

GPS-målinger viser også små deformationer i Grindavík. Der er stadig stor fare for, at jorden kollapser til sprækker i byen, og derfor er det vigtigt at kortlægge nye sprækker og ændringer af kendte estimerede.

Det islandske meteorologiske kontor har opdateret farevurderingen på grund af den vulkanske og seismiske aktivitet. Fareniveauet er blevet reduceret i alle zoner.

En samlet farevurdering for zone 1, Svartsengi, er nu nede på gul (moderat fare).

En samlet farevurdering for zone 4, Grindavík, er nu nede i rødt (høj fare). Bemærk, at farven på zoner repræsenterer den overordnede fare inden for disse zoner. En fare, der vurderes til at være større inden for en zone, er skrevet med fede bogstaver i listen over farer på kortet.

Farevurderingskortet træder i kraft kl. 15:00 i dag, fredag ​​den 19. januar og er gyldigt til torsdag den 25. januar kl. 15:00, medmindre der er væsentlige ændringer.

Hazard_map_IMO_19jan_2024

 

Opdateret 18. januar 15:30 UTC

 

Som rapporteret i nyhederne i går, er der stadig klare tegn på landstigning under Svartsengi, men det er stadig for tidligt at bestemme stigningshastigheden på grund af den seneste vulkanske aktivitet i området. GNSS-målinger evalueres for at give en samlet vurdering af situationen. Det ser dog ud til, at deformationen forbliver magen til den, der blev observeret efter vulkanudbruddet den 18. december.

Omkring 200 jordskælv er blevet registreret nær magmakanalen siden i går, hvor det største måler 1,4 i styrke. Siden midnat er der sket cirka 70 små jordskælv, hvilket er færre end målt dagen før. Vejret har påvirket antallet af jordskælv, der er opdaget i de seneste dage, men antallet af jordskælv ser ud til generelt at være faldet.

Der er fortsat en betydelig risiko i Grindavík på grund af sprækker og potentialet for jordkollaps ind i dem .

Opdateret 17. januar kl. 18:00 UTC

 

 

Magmaophobning fortsætter under Svartsengi. Det er for tidligt at hævde hastigheden af ​​landhævningen kort efter vulkanudbruddet. Eksperter vil fortsat vurdere data fra GNSS-stationer i området for at få en samlet vurdering af situationen. En af målerne, som var placeret nord for Grindavík, gik under lava, men over 20 GNSS-stationer er i området og bliver brugt.

Seismisk aktivitet har været mild over magmakanalen i de sidste 24 timer. Ifølge beregningsmodeller ligger magma lavvandet i den sydlige ende af kanalen, hvor landet ser ud til at være stærkt opbrudt, hvilket gør det lettere for magmaen at nå overfladen. Derfor er der fortsat sandsynlighed for, at nye eruptive sprækker kan åbne sig uden varsel.

Der er stadig fare i Grindavík relateret til sprækker og potentialet for jordkollaps ind i dem. Der er sket betydelige deformationer i forbindelse med graben i den østlige del af byen. Disse bevægelser var for det meste langs de sprækker, der blev dannet den 10. november og allerede var blevet kortlagt.

Gasforurening blev målt i går under arbejde på brønde forbundet til forsyningssystemet i Grindavík. Det islandske meteorologiske kontor overvåger ikke lokal gasforurening i Grindavík. Det skal undersøges nærmere, om gasforureningen er relateret til magmaen, der ligger meget lavt i området. Det skal bemærkes, at farlig gasforurening er blandt de emner, der nævnes i den nuværende farevurdering for Grindavík.

IMO har udsendt et opdateret farevurderingskort. Der er ingen ændringer i den samlede farevurdering for områderne i forhold til tidligere. Kortet træder i kraft klokken 15.00 i dag og gælder til fredag ​​den 19. januar klokken 15.00, medmindre der sker væsentlige udviklinger.

Hazard_map_IMO_17jan_2024

 

Opdateret 16. januar kl. 18:00 UTC

 

Magma fortsætter med at akkumulere under Svartsengi med en hastighed svarende til den, der blev observeret før de sidste to udbrud. Dette var konsensus opnået under et høringsmøde mellem forskere her til morgen. Under udbruddet sidste søndag, i lighed med udbruddet den 18. december, strømmede magma mod øst fra akkumuleringsstedet under Svartsengi, hvilket skabte en magmaledning, der strækker sig fra Stóra-Skógfell sydpå under Grindavík. Beregningsmodeller understøtter denne observation og indikerer, at magmaens oprindelse var lidt længere mod vest sammenlignet med det tidligere udbrud, hvilket førte til variationer i de seneste GPS-målinger sammenlignet med dem, der blev registreret den 18. december.

Da der dannes en magmakanal tæt på overfladen, forspændes jordskorpen, hvilket får landet over den centrale del af kanalen til at aftage og danne en graben. Derudover er jorden forhøjet på hver side af den. Beregningsmodeller, der blev gennemgået på høringsmødet, viser, at GNSS-stationen i Svartsengi er placeret i kanten af ​​kanalen, hvor jorden hæver sig i takt med, at ledningen dannes. Nu, to dage efter kanalens dannelse, forventes Svartsengi GNSS-stationen at vise nedsynkning, hvis magmaakkumuleringen er ophørt. Dette er dog ikke observeret, hvilket indikerer, at magmaakkumulering fortsætter som før.

Magmakanalen, der blev genereret i udbruddet, der begyndte i søndags, ligger lidt længere mod øst end kanalen, der strakte sig under Grindavík den 10. november. Data indsamlet og behandlet af Islands Naturhistoriske Institut og National Land Survey of Iceland afslører, at en ny graben har dannet øst for den, der dukkede op den 10. november. Den nydannede graben måler cirka 800-1000 meter i bredden, som vist på kortet nedenfor. Den største nedsynkning i den er cirka 30 cm, men det er værd at bemærke, at regionen stadig oplever nedsynkninger, og dalen udvides gradvist. Til sammenligning havde graben, der udviklede sig i Grindavík den 10. november, en bredde på omkring 2 km, hvor den mest markante indsynkning målte omkring 1,3 meter.

Inde i denne nyligt dannede graben er tidligere kortlagte sprækker, der var synlige på overfladen, udvidet, og yderligere sprækker er opstået. Følgelig er risikoen forbundet med disse sprækker og muligheden for jordkollaps i dem steget i den østlige del af Grindavík sammenlignet med tidligere.

NyrSigdalur

 

Kort, der viser placeringen og bredden af ​​graben dannet den 10. november (“Mörk sigdals 10-11. nóvember”) og den nyeste graben, der for nylig blev dannet mod øst (“Mörk sigdals 14-15. janúar”).

Opdateret 16. januar kl. 11:45 UTC

 

Der er i øjeblikket ingen synlig aktivitet i de eruptive sprækker, med den seneste lava observeret udgået fra den nordlige sprække kort efter kl. 1 i nat. Seismisk aktivitet fortsætter med at falde, hvilket betyder, at området er ved at stabilisere sig. Omkring 200 små jordskælv blev registreret nær magmakanalen siden midnat, hvilket indikerer, at magma stadig migrerer. Den mest seismiske aktivitet er placeret nær Hagafell, tæt på den første eruptive sprække, der åbnede søndag morgen. På dette tidspunkt er det for tidligt at erklære, at udbruddet er forbi.

GPS-sensorer fortsætter med at registrere jorddeformation i og omkring Grindavík, hvilket illustrerer, at magmakanalen under Grindavík stadig forårsager udvidelse i området. Termiske billeder fra en drone i aftes viser, at sprækker, der tidligere er kortlagt sydvest for Grindavík, er blevet betydeligt større. Der er fortsat betydelige farer i området.


 

Opdateret 15. januar kl. 16:40 UTC

 

Based on webcam footage, it is evident that the lava flow has decreased from the eruptive fissures that opened yesterday. Flow from the southern eruptive fissure, which emerged around noon yesterday near the town‘s border, seems to have ceased. The majority of the remaining lava flow is now directed southwest along the protective barriers, and its trajectory seems to have stabilized.

It is difficult to estimate how long this eruption will last. Seismic activity has decreased, and GPS measurements indicate that the rate of deformation in the area has reduced. However, deformation is still detected near the southernmost part of the magma conduit beneath Grindavík.

Measurements indicate that there has been a displacement of up to 1.4 meters in the past 24 hours, distributed across numerous fissures within the town‘s boundaries. Fresh fissures have developed, and existing ones have expanded. It is possible that additional fissures may emerge on the surface in the next few days.

As previously stated, the eruption sites are extremely hazardous, and the possibility of new fissures emerging without warning cannot be dismissed. This was demonstrated by the eruptive fissure that appeared near the border of Grindavík yesterday, which provided no recognizable warning signs on the monitoring equipment.

Today, there is a mild wind from the northeast at the eruption sites, but it will pick up speed later in the day. Therefore, gas pollution is drifting southwest towards the ocean. Tomorrow, the area will experience winds from the north reaching 10-18 m/s, causing the gas to drift south. Refer to the weather service’s forecast for gas dispersion details.

The Icelandic Meteorological Office continues to monitor the area and is in direct contact with civil protection and response teams in the region about the progression of the event.

Scientists met this morning for a consultation meeting organized by the Icelandic Meteorological Office. They reviewed the most recent data related to the eruption.Top of Form

In the upcoming days, there will be ongoing measurements and the collection of additional data, followed by analysis. These data are being utilized, among other things, to construct models that enhance comprehension of the pre-eruptive indicators that led up to this event and to evaluate the most likely progression of the eruption. Comparisons are also being made between the December 18 eruption and the eruption that began yesterday to enhance understanding of changes in the area and to evaluate the most likely scenarios going forward.

The Icelandic Meteorological Office has issued an updated hazard assessment map based on the latest data. It remains unchanged from the last update. The map is valid until 19:00 on Wednesday, January 17, unless new developments arise.

Hazard_map_IMO_15jan_2024

 

Kort_Hraundreifin_Maelingar140120224

Kort, der viser lavaens udbredelse baseret på målinger udført af det islandske naturhistoriske institut og Islands Universitets institut for geovidenskab. Der blev gennemført undersøgelser to gange i går. Den mørkelilla form viser udstrækningen af ​​lavaen kl. 13.50 den 14. januar, mens den lyse lilla form viser udstrækningen kl. 16.15, næsten 2,5 timer senere. De eruptive sprækker er markeret med røde linjer, mens barriererne konstrueret for at forhindre lava i at nå Grindavík er repræsenteret af orange stiplede linjer

ThykktHrauns_15012024

Kort, der viser tykkelsen af ​​lavastrømmen baseret på målinger kl. 13:50 i går.

Opdateret 14. januar kl. 15:30 UTC

 

 

Udbruddet nær Hagafell-Grindavík har bevaret samme styrke den seneste time eller deromkring.

Seismiske målinger viser, at ved begyndelsen af ​​urolighederne i morges (~2:30 om morgenen), bevægede den magmafyldte digeindtrængen sig først fra den SE-kant af Stóra-Skógfell og fortsatte derefter sydvest til den sydlige ende af Grindavík. Klokken 05.30 havde seismiciteten nået den nordlige ende af Grindavík, og både seismicitet og deformationsmålinger indikerer, at diget siden har forplantet sig under Grindavík by. En ny eruptiv sprække åbnede kl. 12:10 i eftermiddags, lige nord for byen. Lavastrømme ekstruderet fra denne sprække er nu kommet ind i byen.

På grund af digets udbredelse blev eksisterende forkastninger og sprækker reaktiveret, og der er sandsynligvis dannet nye sprækker i Grindavík.

 

Gas distribution

Det islandske meteorologiske kontors vejrudsigt for gasfordeling fra udbruddet ved Hagafell indikerer, at retningen er nord og nordøst, med en hastighed på 3-8 m/s, og vejret er tørt og lyst i dag. Det bliver til tider overskyet med mindre snefald sent i aften og i morgen tidlig. Det vil klare op om eftermiddagen i morgen. Forureningen fra udbruddet breder sig mod syd og sydvest.
GrindavikGas14Jan--002-

 

Nyt farekort udgivet

Det islandske meteorologiske kontor har opdateret farevurderingskortet i lyset af fortolkningen af ​​de seneste data.

Risikoen er steget på alle områder. Farevurderingskortet er gyldigt indtil kl. 19.00, mandag den 15. januar, medmindre andet er angivet.

Hazard_map_IMO_14jan_2024

Opdateret 14. januar kl. 8:20

 

Et udbrud startede klokken 7:57 UTC

Sprækkeåbningen er sydøst for Hagafell-bjerget.

Den sydligste del af sprækken er omkring 900 m fra byen Grindavík.

Åbningen er syd for lavastrømsafbøjningsbarrierer, der bygges nord for Grindavík. Lava strømmer nu mod byen.

Kort_StadsetningGoss2Et billede taget ombord på kystvagtens fly. Sprækkeåbning kan ses med lysene i Grindavík i det fjerne. Et kort, der viser sprækkeåbningen markeret med en rød linje.Kort_StadsetningGoss3

 

Opdateret 14. januar kl. 06:15 UTC

Omkring 03:00 UTC i dag begyndte en intens serie af jordskælv ved Sundhnúksgígar-kraterrækken. 

På tidspunktet for offentliggørelsen er der målt over 200 jordskælv i området, og seismiciteten har bevæget sig mod byen Grindavík. 

So far, the largest recorded earthquake is 3.5 in magnitude, and it was measured at 04:07 UTC at Hagafell. 

Both real-time GPS measurements and borehole pressure readings (from HS Orka) show major changes since the onset of today’s earthquake activity. These observations, in addition to the ongoing seismicity, confirm that magma is moving within the region. 

Our assessment is that the possibility of an eruption is high, and that it could occur imminently.

Skjalftar_1401_Midn

A map showing the latest earthquake activity.

Updated 12 January at 17:45 UTC

 

The Icelandic Meteorological Office has updated the hazard assessment map for the Grindavík – Svartsengi region due to the ongoing unrest on the Reykjanes Peninsula. As before, the map shows an assessment of existing hazards that could occur with little warning within the specified regions. Note that the assessment applies only for hazards within the defined areas, although hazards are possible beyond the confines of the assessed regions.

In terms of colour-coding, the overall assessment for the six zones remains unchanged from the previous map. However, there is a change in the hazard assessment associated with fissures within Grindavík (zone 4). The hazards associated with sudden opening of mapped and unknown fissures within Grindavík is now deemed higher. It should be noted that the hazards associated with fissures is limited to known areas within the municipal boundaries.

Unless otherwise stated, the map is valid until Tuesday, 16 January 2024.

Hazard_map_IMO_12jan_2024

 

Updated 9 January at 13:00 UTC

 

Seismic activity continues to exhibit a pattern similar to that of recent days. The earthquake activity remains relatively low, primarily centered between Hagafell and Stóra Skógfell, where the center of the intrusion is situated. Additionally, there is ongoing seismic activity in Fagradalsfjall, persisting since December 18th.

Land uplift is still being measured in the Svartsengi area, exhibiting a relatively stable trend since the eruption on December 18th. The accompanying image, marked with red dots representing data from the GPS station SENG in Svartsengi, illustrates this trajectory The recent rate of uplift is approximately 5 mm per day, resulting in a current elevation that is about 5 cm higher than before the dike intrusion on November 10th and December 18th last year.

Calculations from models relying on deformation measurements (GPS and satellite images) indicate that the amount of magma accumulated in the reservoir beneath Svartsengi has reached a level comparable to the volume that led to the formation of the magma conduit and the subsequent eruption on December 18th last year. This suggests that there is an increased risk of an eruption in the coming days.

The Icelandic Meteorological Office issued an updated hazard map on January 5th, and it will be reassessed on January 12th.

SENG-9-jan-

 

Relative målinger fra GPS-stationen SENG i Svartsengi fra begyndelsen af ​​oktober 2023 til i dag, viser nord-, øst- og lodrette komponenter (top, midt, bund). Den nederste kurve viser landhævningen i millimeter, med dagens måling angivet med en grøn prik.

Opdateret 5. januar kl. 17:40 UTC

 

Et nyt farekort er udstedt af IMO. Kortet afspejler en farebaseret vurdering af Grindavík – Svartsengi-regionen, foretaget den 5. januar 2024. Farevurderingen er baseret på de seneste overvågningsdata, herunder seismisk aktivitet og jorddeformation, samt geodætiske modelleringsresultater. Vurderingen tager også højde for sandsynligheden for vulkanske farer i hver af de seks zoner, som vist på kortet.

I dagens vurdering påvirker hovedændringen Svartsengi-regionen (zone 1), som nu anses for at være på et moderat fareniveau, hvilket afspejler et fald i forhold til den tidligere version af farekortet. Begrundelsen for denne ændring er, at farevurderingen på grund af dannelsen af ​​større overfladebrud er faldet, da der ikke er dannet nye større brud på det seneste. Derudover gør de seneste geofysiske observationer sammen med vores videnskabelige konsensus Sundhnúksgígar til det bedste sted for et udbrud.

I mellemtiden fortsætter IMO med at overvåge området, og eventuelle ændringer vil blive kommunikeret direkte til civilbeskyttelsen via de sædvanlige kommunikationskanaler.

 

Hazard_map_IMO_5jan_2024

Opdateret 5. januar kl. 14:30 UTC

 

Landhævningshastigheden nær Svartsengi fortsætter med at falde. Eksperter samlet på Meteorologisk Kontor her til morgen bekræftede dette gennem en analyse af GPS-data. Som tidligere rapporteret, signalerer dette en stigning i magmatrykket, hvilket øger sandsynligheden for et nyt digeindtrængen og potentielt udbrud. Det kan dog ikke udelukkes, at dette alternativt kan tyde på et fald i magmatilstrømningen.

Cirka 490 jordskælv har fundet sted nær magmakanalen siden tirsdag den 2. januar. Blandt disse havde 14 en styrke på over 1,0, hvoraf det største målte 1,8 nord for Hagafell. Onsdag den 3. januar indtraf et jordskælv med en styrke på 4,3 nær Trölladyngja, kort efterfulgt af et jordskælv med en styrke på 3,5 og adskillige efterskælv; omkring 900 jordskælv er blevet målt i området.

Den seismiske aktivitet nær Trölladyngja den 3. januar fandt sted langs en anerkendt brudlinje, hvor større jordskælv tidligere er sket flere gange. Der er intet, der tyder på, at disse jordskælv er direkte forbundet med magmabevægelser. Ikke desto mindre er de bemærkelsesværdige ændringer i landskabet i forbindelse med vulkansk aktivitet i Fagradalsfjall, landhævningen nær Svartsengi, magmakanalen nær Sundhnúk den 10. november og udbruddet den 18. december blevet målt på tværs af det vestlige Reykjanes og påvirker seismisk aktivitet i hele regionen .

According to their evaluation, scientists conclude that in the event magma reaches the surface, the most probable site for a subsequent eruption would again be Sundhnúksgígaröðinni, situated between Stóra-Skógfell and Hagafell. However, it is important to remember that dike intrusions do not always culminate in an eruption, as evidenced by the activity at Fagradalsfjall and also during the Krafla fires. 

 

Updated 3 January at 12:30 UTC

At 10:50 AM, an earthquake of magnitude 4.5 occurred near Trölladyngja, followed shortly by another earthquake measuring 3.9 at 10:54 AM and a series of aftershocks. The earthquakes occurred at a depth of approximately 5 km and were likely triggered in response to stress released from earth movement elsewhere on the Reykjanes Peninsula. These earthquakes were widely felt in the southwest region of Iceland.

The location of the earthquakes is about 20 km NNE of Svartsengi, where land rise due to magma accumulation is ongoing. 

The accompanying image shows the location of the earthquake that occurred at 10:50 AM and its impact area.

Gikkskjalftar-trolladyngja-3-jan

Updated 2 January at 14:00 UTC

 

The rate of ground displacement at Svartsengi is decreasing. Experts gathered at the Meteorological Office this morning confirmed this through an analysis of GPS data.

The deceleration of inflation is an indication that magma pressure is rising, increasing the chances of new dike intrusion and also volcanic eruption. This is a similar change in ground displacement that was observed at the end of the day on December 15, which culminated in an eruption three days later. However, it is difficult to assert whether this pattern will repeat.

The first signs of an impending volcanic eruption are a sudden increase in seismic activity, and such signs were observed shortly before the eruption began on December 18.

In recent days, seismic activity in the area has been relatively consistant, with around 200 earthquakes recorded per day. Most of the earthquakes measure below magnitude 1.0, but around 30 earthquakes with magnitudes exceeding 1.0 have been recorded since December 29, with the largest being a magnitude 2.1 located in the northern part of Grindavík.

Continued scientific assessment indicates that, should an eruption occur, the Sundhnúkur crater row, between Stóra-Skógafell and Hagafell, is the most probable location for an eruption. However, it is important to note that magma migration does not always result in an eruption, as demonstrated by the activity at Fagradalsfjall and in the Krafla Fires.

The hazard assessment map issued by the Meteorological Office onDecember 29 remains unchanged and is valid until January 5.

Seismic activity continues to be measured west of Fagradalsfjall, where around 100 small earthquakes have been recorded since December 29. Further analysis of the monitoring data will soon be conducted to obtain a clearer picture of the situation at Fagradalsfjall.

 

Updated 29 December at 15:15 UTC

The ground continues to inflate at Svartsengi. At the GPS station Svartsengi (SENG), the land has now reached a similar height as measured just before the eruption on 18 December. The rate of uplift since 18 December has remained constant, which is different from the situation before the last eruption, where uplift slowed in the days before the eruption. However, it is difficult to assert that the uplift will slow down before the next eruption, though this has been the case in eruptions on the Reykjanes Peninsula in recent years, and it was also noted during the Krafla Fires. Uncertainty remains about how much magma pressure needs to build up before magma starts moving towards the surface.

The current uplift is not accompanied by as much seismic activity as before. The reason for this is that significant stress in the area was released during the events on 10 November and 18 December. Therefore, considerably more magma needs to accumulate before seismic activity increases from its current level. Before the last eruption, there were several earthquakes over magnitude 3 and one over magnitude 4. Similar seismic activity can be expected in connection with the next magma intrusion.

As magma accumulation continues under Svartsengi, the likelihood of another magma intrusion and an eruption increases with each passing day. It is most likely that the next eruption will occur in the Sundhnúkur, between Stóra-Skógfell and Hagafell. It is important to note that magma intrusions do not always lead to an eruption, as shown by the activity at Fagradalsfjall and in the Krafla Fires.

The Icelandic Meteorological Office has issued an updated hazard map, based on the joint interpretation of data at a status meeting held today, 29 December. The overall assessment of hazard levels within the areas remains unchanged from the last update. However, changes have been made to the list of potential hazards within area 4, Grindavík, where risks due to possible lava flow and gas pollution have been added. The changes are due to increased chances of an eruption north of Grindavík. This hazard map will be reviewed on 5 January 2024.

In the meantime, IMO continues to monitor the area and any changes will be communicated directly to civil protection via the usual communication channels.

Haettusvaedi_VI_29des_EN-2

Updated 27 December at 14:20 UTC

Since 22 December, around 730 earthquakes have been recorded in the vicinity of the magma intrusion, of which 40 had a magnitude above M1. The largest earthquake over this period had a magnitude of 2.1 on 26 December, north of Hagafell. Most of the earthquakes are occurring at a depth of 4 km. Additionally, between 22 December and today, around 140 earthquakes have been located on the western side of Fagradalsfjall. Five of these earthquakes were above M1 in size and the overall depth range was 4 to 7 km.

Ground deformation continues in the Svartsengi region, and the rate of deformation is now similar to before the eruption on 18 December 2023. This means that magma continues to accumulate under Svartsengi. Therefore, it is increasingly likely that another magma intrusion will occur, possibility leading to a second volcanic eruption. Geodetic modelling results indicate that over 10 million m3 of magma were sourced from beneath Svartsengi to feed the intrusion that formed on 18 December, which led to the eruption. Based on the ongoing uplift rate, it will take one to two weeks for the same amount of magma to accumulate again underneath Svartsengi. There is still significant uncertainty on when the built-up in magma pressure will be sufficient to trigger the next magma intrusion.

It should be noted that the original magma intrusion, which formed on 10 November, extended 15 km from Kálfafellsheiði in the north to the southwest of Grindavík, just offshore. This means that magma propagated at depth beneath the entire area, including the town of Grindavík. However, the most likely source area for the next eruption is between Stóra-Skógfell and Hagafell. Based on insights from the December 2023 eruption, the likelihood for the next event increases day by day. 

The hazard assessment map issued on 22 December 2023 remains valid. Assuming an unchanged situation, a new map will be issued on 29 December.

SENG-27-des-2023

Time-series of continuous GPS solutions from station Svartsengi (SENG). The graph shows ground displacements in three components over the past 90 days. From bottom to top they are: up, east, and north, all measured in millimetres. The blue, vertical line shows the timing of the 10 November magma intrusion, and the red line the volcanic eruption on 18 December 2023. Each data point represents a 24-hour solution, and the vertical component shows clearly the ongoing ground uplift at Svartsengi.

Updated 22 December at 17:00 UTC

As announced yesterday, the fissure eruption at Sundhnúksgígar has ended. This indicates a temporary cessation of eruptive activity. In the last 24 hours, nearly 90 earthquakes were recorded in the Grindavík, Sundhnúksgígar, and Svartsengi regions. The largest earthquake was M1.6 west of Hagafell, just after 16:00 UTC yesterday (21 December). Overall, seismicity levels are low but variable on a daily basis.

According to GPS and satellite-based measurements, ground uplift in the Svartsengi region was apparent immediately after the eruption began on the evening of 18 December. Initial measurements show that the rate of uplift is greater than before the eruption occurred. This signifies that magma accumulation continues unabated beneath Svartsengi. This development will likely lead to another dike intrusion and, ultimately, a volcanic eruption. In the event of an eruption, the most likely source region is between Stóra-Skógfell and Hagafell.

Continuous GPS measurements show that the rate of daily ground uplift at Svartsengi between 10 November, when the magmatic intrusion formed, and 18 December progressively declined. This process is likely to repeat itself, meaning that the next dike intrusion could begin with little warning when the uplift rate decreases again. Therefore, the likelihood of an eruption increases day-by-day.

Following confirmation of the end of the 18 December eruption, the Icelandic Meteorological Office has issued a new hazard assessment. The hazard map comes into effect at 16:00 UTC today (22 December), and it remains valid until 18:00 UTC on 29 December. The main changes affect zones 2 and 3, where hazard levels have reduced from very high (purple) to high (red). The hazard assessment for all other zones is unchanged. Notably, the assessment for Grindavík is unchanged from the previous map, and the hazard level remains considerable. We emphasise that conditions can change rapidly, and that weather conditions can significantly affect the sensitivity of our monitoring networks. Under such conditions, the warning time could shorten considerably.

The weather forecast for Grindavík on 23 December calls for northeast wind 10-15 m/s, intermittent snowfall, and possibly drifting snow. Temperatures will be low, between 3 to 5°C. On 24 December, winds from the north 13-18 m/s with occasional snow showers, but 10-15 m/s in the afternoon with decreasing snow showers. Intermittent drifting snow can be expected. Temperatures will be from 0 to 2°C


Haettumatskort-22-desember-2023-enska-

The latest hazard assessment map, published on 22 December, 16:00 UTC. It is important to note that new hazards could arise with little warning within the specified areas. Additionally, the assessment applies only to the specified areas, whereas hazards could extend or occur beyond the identified zones.

Updated 21 December at 12:55 UTC

Scientists who flew over the eruption site this morning confirm that no eruptive activity is visible and that lava flow from the craters seems to have ceased. Glowing is still visible in the lava field, possibly within closed channels. This was also confirmed by an Elfu staff member in Sýlingarfell. The activity appears to have diminished late last night or very early this morning. However, it is still possible that lava is flowing in closed channels, so it is premature to declare the eruption over.

Earthquake activity has continued to decrease, and over the last 24 hours, approximately 70 minor earthquakes were measured over the magma conduits. The largest quake yesterday occurred at 14:27 and measured 1.4 in magnitude, while the largest since midnight last night was magnitude 1.9. Deformation measurements at Svartsengi show little movement, but measurements over the next few days will further clarify the situation there.

Gas dispersion, mainly due to the degassing of the lava field, will be southeastward and out to sea today. Tomorrow, with a slower northeast wind, the gas will travel southwest.

At this point, it is difficult to predict the continuation of the eruption, but scientists at the Meteorological Office are constantly assessing the latest data and continue to closely monitor the area.


Updated 20 December at 18:50 UTC

The eruption that began in the Sundhnúksgígar crater row on 18 December started with considerable force, and the warning period was short. About 90 minutes passed from the first signs of seismicity until the eruption began. The eruption occurred on the magma intrusion that formed on 10 November. The magma is sourced most likely from beneath Svartsengi, where the land has risen repeatedly since 2020.

In the last 24 hours, the highest activity in the eruption has remained around the middle of the fissure that opened on 18 December. Seismic activity has been relatively steady, and there have been little changes in deformation since the eruption began. Considering this, the Icelandic Meteorological Office (IMO) assesses that the likelihood of a new eruption forming without warning nearby Grindavík has decreased. Therefore, IMO has issued a new hazard assessment map that will take effect tomorrow, Thursday, 21 December at 7:00 UTC. The hazard assessment map is valid until 28 December. It should be noted that although the likelihood of vent formation within area 4 has decreased, the hazard level in that area is nevertheless considered substantial. Even though the activity has decreased since the eruption began, the intensity of the eruption is still significant and comparable to eruptions at Fagradalsfjall. It has also been shown that the magma can reach the surface quickly, leaving little time to issue warnings.

Hazard_map_VI_20des_DRAFT

Because of the volcanic eruption that began at Sundhnúksgígar crater row on 18 December, there is an increased likelihood of further vent openings on the original fissure. Based on the sudden onset of the eruption at Sundhnúksgígar, the warning time for new fissure openings could be very short.


Updated 20 December at 17:00 UTC

The vigor of the eruption continues to diminish. New images of the area show that currently two craters are erupting. The most active today is the crater directly east of Sýlingarfell which is the southernmost of the craters that were active yesterday.

Lava continues to mostly flow east from the volcanic vents, but a lava tongue has also run west, north of Stóra-Skógfell. The southernmost edge of the lava does not appear to be advancing. Satellite images taken last night show that the lava field is about 3.7 square kilometers in size.

Wind will turn northwesterly tonight and tomorrow, and pollution will be transported southeastward and out to sea. The Icelandic Meteorological Office regularly issues gas pollution forecasts.

There has been a significant decrease in earthquake activity, and over the last 24 hours, about 80 small tremors have been measured over the magma conduits. The largest quake was 2.2 in magnitude at 10:55 am yesterday morning, and the largest since midnight is 1.2 in magnitude.

Hraunflaedi-20-des

Updated 19 December at 18:30 UTC

The eruption continues to weaken. New aerial images of the area show that there are now three vents erupting southeast of Stóra-Skógfell, down from the previous five. The lava has mostly flowed east from the eruption site, but there is also a lava tongue flowing west from the region north of Stóra-Skógfell.

Since the eruption began, about 320 earthquakes have been measured over the magma channels. The largest earthquake, with a magnitude of 4.1, occurred at 23:25 on Monday. After midnight, seismic activity significantly decreased, and since 12:00 today, only 10 earthquakes have been recorded in the region. Following the eruption at Sundhnúksgíga, the land in Svartsengi subsided more than 5 cm. Previously, the land had risen there by about 35 cm since the formation of the magma channel on November 10. It is too early to determine if magma will continue to accumulate under Svartsengi and whether the land will start to rise again.

While the eruption continues at Sundhnúksgíga, there is an increased likelihood that more vents may open along the original fissure as well as further north or south. Looking back at the lead-up to the eruption reveals that there were approximately 90 minutes between the first indicators and the start of the eruption. Therefore, the warning time for new vent openings at Sundhnúk could be very short.


Updated 19 December at 14:30 UTC

The size of the volcanic eruption at Sundhnúksgígar continues to diminish. The lava flow is estimated to be about one-quarter of what it was at the beginning of the eruption on 18 December, and a third of the original fissure is active. The lava fountains are also lower than at the start of the eruption, reaching about 30 meters at their highest. These figures are based on visual estimates from a reconnaissance flight early on 19 December.

The development of the eruption is similar to recent eruptions at Fagradalsfjall, where the fissures are starting to contract and form individual eruption vents. Presently, there are about five eruption vents spread along the original fissure.

According to information from scientists who went on a second helicopter flight with the Icelandic Coast Guard at around 04:00 UTC today, the total length of the fissure eruption has not changed much from the beginning. There was little activity at the southern end of the fissure near Hagafell, and the majority of the lava flow is heading east towards Fagradalsfjall. Two streams reach west, both north of Stóra-Skógfell.

At the time of publication, the volcanic plume is drifting from the west and northwest. Gas pollution might be noticeable in Vestmannaeyjar today, but not elsewhere in populated areas. According to the weather forecast, gas pollution might be detected in the capital area late tonight or tomorrow morning.

A new hazard assessment map is being prepared, and it will be published later today.

Iceye-19-des-nytt

Amplitude image from an ICEYE satellite acquired at 03:11 this morning (19 Dec. 2023). Preliminary analysis of this image show the new eruptive fissure (yellow line) and lava flow (colored area). Notice that he dams built around Svartsengi are clearly visible.

Updated 19 December at 3:00

The intensity of the volcanic eruption, which started about four hours ago, is decreasing. This is evident from seismic and GPS measurements. The fact that the activity is decreasing already is not an indication of how long the eruption will last, but rather that the eruption is reaching a state of equilibrium. This development has been observed at the beginning of all eruptions on the Reykjanes Peninsula in recent years.

The eruptive fissure is about 4 km long, with the northern end just east of Stóra-Skógfell and the southern end just east of Sundhnúk. The distance from the southern end to the edge of Grindavík is almost 3 km.

The Icelandic Meteorological Office continues to monitor the activity and is in direct contact with civil protection and response units in the area. A meeting of scientists will be held tomorrow morning to evaluate the overnight development of the eruption.

This news will be updated at 09:00 on 19 December.

Eldgos_19des_stadsetning_0300_DA


Updated 19 December at 02:10

According to the latest aerial observations and seismicity, the eruption fissure is expanding to the south. At the time of publication, the southern end of the fissure was close to Sundhnúkur. 

The eruption is located on the dyke intrusion that formed in November. The rate of lava discharge during the first two hours of the eruption was thought to be on a scale of hundreds of cubic metres per second, with the largest lava fountains on the northern end of the fissures. 

Lava is spreading laterally from either side of the newly opened fissures. From real-time GPS measurements, significant ground deformation has accompanied the opening of the eruption fissures. 

Since midnight on 19 December, the level of seismicity at the eruption site has decreased. Additionally, estimates of fissure lengthening suggest that the eruption has decreased in intensity since its onset at 22:17 on 18 December.


Updated 18 December at 23:00

 

At 22:17 this evening, a volcanic eruption began north of Grindavík on the Reykjanes peninsula. The eruption is located close to Sundhnúkagígar, about four kilometres northeast of Grindavík, and it can be seen on nearby web cameras. The eruption was preceded by an earthquake swarm that started at 21:00.

 

A Coast Guard helicopter will take off shortly to confirm the exact location and size of the eruption.

More information will be available soon.


Updated 16 December at 14:00 UTC

At this stage it is too early to say if magma accumulation at Svartsengi has stopped and the inflation is over. The rate of deformation has decreased somewhat in recent days, but more data is needed to interpret the possible development of the activity in Svartsengi.

Scientists will continue to analyze the data in the coming days. 

A new hazard map will be released on Wednesday December 20th, which will reflect the interpretation of the latest data.


Updated 15. December at 13:00 UTC

Generally weak seismicity continues in the area affected by the dike and is mostly concentrated near Hagafell.  Since Tuesday December 12, 460 earthquakes, 30 of which were greater than M1.0, have been measured. The largest earthquake in this time was M2.8 near Hagafell on Tuesday morning. Data from GPS stations and satellite images show that uplift due to the accumulation of magma continues around Svartsengi. While magma continues to accumulate in this area, further dikes or an eruption remain possible.

The hazard map published on December 6 Icelandic map here below continues to be valid until December 20. Conditions inside and outside the demarcated hazard zones can change with little warning.

Haettusvaedi-13des-png


Updated 13. December at 11:15 UTC

The area around Svartsengi continues to inflate. The rate of inflation has decreased somewhat since Friday, but it is still greater than it was prior to the formation of the dike that traveled under Grindavík November 10 .

While magma continues to accumulate around Svartsengi, further dikes or an eruption remain possible.

If another dike forms it is considered to be likeliest that it would follow the same path as the November 10 dike. The most likely location for a potential eruption under these conditions is assessed to be north of Grindavík in the direction of Hagafell and the area around Sundhnúkagígar. 

Seismic activity continues at a similar level to the previous days. It is generally weak and mostly in the area around Hagafell.


Updated 6. December at 18:00 UTC

Latest geodetic modelling results suggests that the magma inflow to the dike that formed on November 10 has likely ceased. The chances of an eruption happening along the dike at this time have therefore significantly decreased. However, magma accumulation continues beneath Svartsengi.  

The ongoing activity at Svartsengi, which began in October, is not yet over and a new chapter may have begun with an increased chance of a new magma propagation and, subsequently, increased likelihood of an eruption. 

As previously mentioned, the dike beneath Grindavík was fed by magma accumulating beneath Svartsengi. It is likely that this sequence of events will repeat. When looking at the overall pattern with repeated magma accumulation, it can be estimated that the next magma propagation from Svartsengi might be on a smaller scale than the one previously formed on November 10. A magma propagation could persist for several hours or days with an increased risk due to seismic activity and deformation during that period. 

Signs of a magma propagation include a sudden increase in seismic activity and rapid changes in ground deformation. These signs can be observed on instruments several hours before the magma propagation is likely to pose a threat to Svartsengi or Grindavík. If a magma propagation occurs, the Icelandic Meteorological Office will immediately activate response plans for public safety. 

Following a magma propagation, the likelihood of an eruption increases. As mentioned above, it is most likely that magma will propagate from Svartsengi into the previously formed dike on November 10. Making it the most likely area for an eruption. 

It is not possible to estimate when the next magma propagation will occur. The uncertainty is considerable, and a magma propagation could happen in the next few days or possibly after several months. 

The Icelandic Meteorological Office continues to monitor the area closely and continues to monitor any signs of magma propagation and other changes that could pose further danger in the area near Svartsengi and Grindavík.

Comparison of Svartsengi and Krafla Fires

In the last week, approximately 300-500 earthquakes were detected in a 24-hour period around the dike intrusion. The largest earthquake was a M2.7 near Hagafell on Friday evening. Since midnight today, about 90 earthquakes have been detected along the dike, all measuring below a M2.0. The majority of seismic activity continues to be concentrated along the middle of the dike at about 3-4 km depth. Due to subsidence in Svartsengi the stress in the Earth’s crust has changed. Until the previous stress level is reached, it can be expected that minor seismicity continuous in the region.

Despite the recent decrease in seismic activity in the last weeks, further unrest can be expected on the Reykjanes Peninsula. Examples of similar unrest can be seen in the Krafla Fires that began in 1975. Over a 10-year period, there were 20 magma propagations, with 9 of them resulting in an eruption (see explanatory image below). In the Krafla Fires, all of the magma propagations fed the same dike but they varied in size. A similar recurrence can also be observed in the activity around Fagradalsfjall.

De seneste geodætiske modelleringsresultater indikerer, at mængden af ​​magma, der i øjeblikket er akkumuleret under Svartsengi, er betydeligt mindre end volumen akkumuleret før digets indtrængning den 10. november. Når man ser på magma-akkumuleringen og magma-udbredelsen i Krafla-brandene, er det tydeligt, at den største mængden af ​​magma havde ophobet sig i Krafla-calderaen før det første vulkanudbrud. En mindre mængde magma akkumulerede i calderaen, før den næste magma-udbredelse fandt sted. Det kan estimeres, at en lignende udvikling vil ske i forhold til magmaophobning under Svartsengi, og der skal ophobes en mindre mængde magma, før den udløser den næste magmaudbredelse ind i diget. Det er sandsynligt, at langsomt stigende seismicitet vil blive opdaget, før en ny magmaudbredelse finder sted, hvilket indikerer øget tryk under Svartsengi.

Kroflueldar-enska

Billedet viser samspillet mellem dannelsen af ​​diger og løft midt i Krafla-krateret. Det nederste billede viser højden af ​​land inden for Krafla-krateret, mens det øverste viser afstanden mellem Krafla-krateret og urolighederne. (Páll Einarsson og Bryndís Brandsdóttir, 2021)

Opdateret 1. december kl. 16:50 UTC

 

Seismiciteten på halvøen fortsætter med at falde. I de sidste par dage har det automatiske jordskælvslokaliseringssystem registreret relativt få jordskælv, for det meste mikrojordskælv under størrelsesordenen 1. Den seneste seismicitet er koncentreret i området mellem Sýlingarfell og Hagafell, hvor diget højst sandsynligt fødes af magma, der ophobes under Svartsengi. Nogle deformationer detekteres stadig på cGPS-stationerne tæt på diget, men signalet tolkes nu hovedsageligt som skorpens reaktion på den igangværende inflation i Svartsengi-området.

Selvom aktiviteten langs diget og dets omegn nu foregår med meget lav intensitet, fortsætter inflationen, som startede i Svartsengi få dage efter digets dannelse, med et nogenlunde stabilt tempo. Nogle cGPS-stationer omkring Svartsengi og Mt. Þorbjörn viser en langsom faldende tendens, men andre stationer viser stadig en konstant tendens, hvilket tyder på, at indstrømningshastigheden af ​​magma i dybden ikke er reduceret væsentligt.

Processen, der begyndte den 25. oktober med en betydelig seismisk sværm og toppede den 10. november med dannelsen af ​​et 15 km langt magmatisk dige, er ikke slut. Med sikkerhed kan det konstateres, at en fase er startet, hvor et lignende hændelsesforløb kan gentage sig med tiden.

På dette stadium er det dog svært at sige, hvornår den næste energiske indtrængen af ​​magma på lavere dybde kan forekomme, og om den vil forekomme i et lignende område eller ej. IMO fortsætter med at opretholde overvågningen af ​​området på et højt niveau.

 

Opdateret 29. november kl. 17:00 UTC

The seismic activity has continued to slowly decrease over the last two days. Yesterday, about 340 earthquakes were measured near the magma intrusion in the area east of Sýlingarfell, and since midnight today, around 150 earthquakes have been recorded. Most of the earthquakes have been smaller than magnitude 1.0.

The rate of uplift near Svartsengi has been decreasing, but it is still ongoing at a rate of about 1 cm per day. The majority of the displacement in the region is currently attributed to inflow under Svartsengi with a smaller portion flowing into the magmatic intrusion. In other words, the deformation measured and modeled at Svartsengi is now much greater than that seen near the magma intrusion, but all deformation signals are slowly diminishing. Observed signs of inflow into the magmatic intrusion is now limited to the area east of Sýlingarfell. Despite the slowing down of seismic activity and deformation, an eruption is still considered to be possible. If an eruption does occur, the location thought to be most likely is east of Sýlingarfell.

Seng-29-nov

Here is a timeline for the GPS station Svartsengi (SENG). It shows movements over the last 90 days in the north, east, and vertical directions. The blue line marks the magma intrusion from November 10th until today.

SENG-29-nov-fra-10-nov

This image depicts the movements from the station since November 10th until today.

Updated 27. November at 16:30 UTC

Seismic activity has been relatively stable for the past few days with a daily rate of about 500 earthquakes in the area of the magmatic dike. Most of the seismicity continues to be nearby Sýlingarfell and Hagafell. Around midnight a short-lived seismic swarm commenced in the vicinity of Sýlingarfell and lasted for roughly one hour. A total of 170 earthquakes were detected in the area at a depth of 3-5 km. The earthquakes were almost all very small with one M3.0.

Data from GPS stations and satellite images show that uplift continues in the area of Svartsengi and deformation is still ongoing along and around the dike. The elevated seismic activity which occurred around midnight isn´t associated with any changes to the ongoing deformation. Both seismic and deformation data suggest that magma continues to accumulate beneath Svartsengi and to flow into the middle portion of the dike which formed on 10 November. The seismic swarm that occurred this night might indicate increasing pressure within the dike.

In light of the available data and the newest analysis, an eruption along the dike is still considered likely as long as the magma inflow continues. It is assessed that the area with the highest likelihood for an eruption is in the middle part of the dike between Hagafell and Sýlingarfell. The hazard map published by the IMO on 22 November remains valid.

Additional geodetical modelling has been performed to reconstruct the evolution of the dike which formed on 10 November. These newest results suggest that the dike at depth could be wider than  initially assessed. The time needed to solidify the magma that intruded into the dike would be therefore estimated to be on the order of a few months.

Yfirfarnir-skjalftar-27-nov

This picture shows reviewed earthquakes since 24. November.

Updated 24. November at 13:30 UTC

Yesterday, around 650 earthquakes were measured near the dike intrusion north of Grindavík, and since midnight today, nearly 300 earthquakes have been detected. Most of the earthquakes are below M1.0, but the largest earthquake in the last two days was M2.7 near Hagafell. The seismic activity continues to decrease.

Data from GPS measurements show that deformation continues near Svartsengi, and deformation is still measured around the dike intrusion. However, there are indications that the rate of deformation has decreased based on data from the past week. Though, the interpretation of deformation data is complex at this stage. This is because other processes, such as fault movements related to earthquakes and the viscoelastic response of the Earth’s crust to unrest in the area, have an impact on the deformation signals.

Considering the latest interpretation of all data, the likelihood of a volcanic eruption at some location along the length of the magma intrusion persists. It is possible that magma could emerge in the area between Hagafell and Sýlingarfell. However, as crustal relaxation continues to occur and seismicity decreases, along with a decrease in magma inflow to the intrusion, the likelihood of an imminent volcanic eruption diminishes with time.

Graf-25.-november

Overview of seismic activity from Friday, November 17th. The upper graph shows the number of earthquakes per hour, and the lower graph shows the number of earthquakes per day. The effects of strong wind and heavy sea swell on the Reykjanes Peninsula on November 21st and 22nd are evident in fewer recorded earthquakes due to reduced sensitivity of the seismic network during that time.


Updated 23. November at 12:30 UTC

On 21 November, approximately 300 earthquakes were detected in the region of the magma intrusion. From midnight on 22 November to 18:00 UTC on the same day, around 100 earthquakes had been recorded in the same region, which is considerably less than in recent days. Additionally, the intensity of earthquakes above magnitude 2.0 has decreased. During the period of severe weather on 21 and 22 November, efforts were made to assess how weather conditions and ocean swell influences IMO’s monitoring systems.

Magma inflow rates and crustal adjustments related to the formation of the intrusion continue to diminish. Additionally, crustal uplift near to Svartsengi continues at a similar pace. Geodetical models based on data from 21 November suggest that the influx into the intrusion is greatest near to the Sundhnúkur crater row, about 4 km northeast of Grindavík. Minor surface displacements have been detected within the graben region in and around Grindavík.

The likelihood of a volcanic eruption at some location along the length of the magma intrusion persists. It is possible that magma could emerge in the area between Hagafell and Sýlingarfell. However, as crustal relaxation continues to occur and seismicity decreases, along with a decrease in magma inflow to the intrusion, the likelihood of an imminent volcanic eruption diminishes with time.

Based on the latest data, and considering the evolution of activity since 10 November, the likelihood of a sudden eruption within the Grindavík urban area is decreasing daily, and it is presently assessed as low. It can be assumed that newly emplaced magma beneath Grindavík has solidified partially, thereby reducing the likelihood that the magma will reach the surface within the city limits. However, we emphasise that the possibility of a volcanic eruption at some point along the length of the intrusion, particularly between Hagafell and Sýlingarfell, remains plausible.

It is apparent that there is a strong connection between crustal uplift in the Svartsengi region and the sudden, initial propagation of the magma intrusion on 10 November. Models indicate that the magma in the reservoir beneath Svartsengi may have flowed eastward towards the Sundhnúkur craters, subsequently forming the 15-km-long volcanic intrusion. While crustal uplift in Svartsengi continues, it is expected that the accumulating magma may flow again eastwards, potentially reactivating the intrusion. It is also feasible that a magma intrusion could form to the west of the magma body accumulating beneath Svartsengi. Precursors to such an event would include pronounced seismicity and rapid ground displacements, both of which are monitored closely by IMO continuously.


Updated 21. November at 15:30 UTC

 

Since midnight today, 165 earthquakes have been recorded due to the ongoing volcanic unrest, all below magnitude 2.0 in size. The level of seismicity today is considerably lower than in the recent days, when 1,500-1,800 earthquakes were recorded each day. It can be expected that the intense weather affecting the country has an impact on the sensitivity of the seismic monitoring system to detect the smallest earthquakes, making it difficult to assess whether the seismic activity is decreasing overall.

The deformation associated with the magma intrusion that formed on November 10 continues. Likewise, crustal uplift continues near Svartsengi. The speed of the uplift at Svartsengi has remained almost the same during the past 24 hours.

In collaboration with specialists from the University of Iceland, IMO continues to monitor the area as effectively as possible, constantly re-evaluating and interpreting the data received.

As mentioned before, IMO has increased surveillance in and around Grindavík and the area around Hagafell. The effectiveness of this surveillance depends on the high sensitivity of earthquake and real-time GPS measurements, which are highly dependent on weather conditions. Given the weather forecast for the next two days, which indicates precipitation and significant wind, it can be expected that both seismic monitoring and real-time GPS observations will be affected. Ocean waves also create microseisms that overwhelm the low-frequency detection capabilities of seismometers on the Reykjanes Peninsula. Fog and hail showers could also affect the visual confirmation of an eruption, adding to the monitoring and assessment uncertainty.

 

Updated 20. November at 13:20 UTC

Since midnight today, over 700 earthquakes have been detected in the region of the magma intrusion, the largest of which was magnitude 2.7 near to Hagafell. 

In recent days, between 1,500 and 1,800 daily earthquakes have been measured in the region, with the largest event registering magnitude 3.0 last Friday (17 November). Based on radar imagery from 18 and 19 November 2023, the latest interferogram of the magma intrusion and the surrounding area shows significant crustal uplift in the vicinity of Svartsengi. The newly processed interferogram was reviewed by experts during the weekend (18 – 19 November) from the Icelandic Meteorological Office, the University of Iceland, and the Department of Civil Protection and Emergency Management. The results were also discussed in today’s status meeting, held at IMO. The rapid, ongoing uplift close to Svartsengi is occurring in the same area where uplift was measured before the magma intrusion formed on November 10. Geodetic models derived from satellite images show that the uplift in Svartsengi area is considerably faster than before. Generally, when a magma intrusion forms, subsidence occurs above the centreline of the intrusion, as seen in Grindavík, with signs of land uplift discernible adjacent to the intrusion. Crustal uplift in the Svartsengi region due to magma accumulating at depth has been measurable since the intrusion began to form on 10 November. Initially, the uplift sign was influenced by the formation of the intrusion, but now the dominance of deep magma recharge is apparent.

The clear sign of crustal uplift in Svartsengi region does not change the likelihood of an eruption from the magma intrusion. This is assessed, amongst other things, on the fact that the Earth’s crust over the magma intrusion is much weaker than the crust over the uplift region close to Svartsengi. As long as there is not significant seismicity in the Svartsengi region, there is not a high likelihood of an eruption at that location. Moreover, an eruption is still deemed more likely from the intrusion, particularly if there is a sudden, large inflow of magma into the intrusion.

Our monitoring and hazard assessment preparations are still based on the assumption that the situation could change suddenly with little warning. The Icelandic Meteorological Office, in close cooperation with experts from the University of Iceland, will continue to monitor the area closely, with the goal of continually interpreting and evaluating all available monitoring observations.

20-nov-vincent

COSMO-Skymed interferogram spanning 24-hours between 18−19 November at 06:41. The broad uplift signal visible in orange/red around Svartsengi is indicative of a deep inflation (>5 km) taking place.

Updated 18 November at 15:00 UTC

Seismicity related to the magma intrusion that formed suddenly a week ago remains high and constant. Approximately 1,700 earthquakes have been recorded in the last 24 hours, 1.000 of those recorded since midnight. The largest earthquake during the last 24 hours had a magnitude of 2.8 and occurred near Hagafell, 3.5 km NNE of Grindavík.


Updated 17 November at 12:00 UTC

Seismicity related to the magma intrusion that formed suddenly a week ago remains high and constant, although the level of activity is substantially lower than 10 – 12 November 2023. Approximately 2,000 earthquakes have been recorded in the last 24 hours, with most activity in an area north of Hagafell, towards the Sundhnúkar craters. Most of the seismicity is micro-earthquake activity comprising earthquakes under M 1. The largest earthquake during the last 24 hours occurred at 06:35 near Hagefell; it had a magnitude of 3.0.

According to GPS measurements, ground deformation continues but at a decreasing rate. The latest geophysical models based on GPS data and satellite imagery indicate that the largest movements in the magma intrusion are occurring north of Grindavík, near Hagafell. If magma manages to reach the surface, Hagafell is thought to be a prime location for an eruption.

Subsidence over the magma intrusion remains active, although measurements show a slight slowdown from day to day. Presently, GPS stations located in and around Grindavík, near the center of the subsidence zone, show about 3–4 cm of subsidence per day.

Based on the interpretation of the latest data and model results, a volcanic eruption remains likely, with the highest likelihood of it starting north of Grindavík near Hagafell.

Grindavik_situation_map_20231116_DA

A map showing the extent of the subsidence over the magma instrusion in and around Grindavík. A GPS station (GRIC) located near the center of the subsidence has recorded a total subsidence of 25 cm since the beginning of the event.

 


Updated 16 November at 17:50 UTC

Over the past few days, seismicity near the magma intrusion has remained relatively stable. As of 17:00 today, about 1,400 earthquakes have been recorded since midnight, the largest being 2.9 in magnitude, sourced near Hagafell just after 13:00. Most of the earthquakes were under magnitude 2, with the highest concentration of activity near Hagafell.

Deformation related to the magma intrusion continues to be measured, although it has slowed slightly since yesterday. The latest models, derived from GPS measurements and satellite data, still suggest that the largest movements of the magma intrusion are north of Grindavík near Hagafell. If magma manages to break through to the surface, it is most likely to happen in the region of Hagafell.

Eartly today, sulphur dioxide (SO2), a type of volcanic gas, was measured from a borehole at Svartsengi, located just north of Þorbjörn. The borehole extends eastward to considerable depth towards the Sundhnúkur crater row. The base of the borehole therefore reaches close to the location in the crust was the magma intrusion is located. Further gas measurements will be conducted tomorrow, 17 November. The detection of volcanic gas from such a borehole is another independent confirmation of the presence of magma north of Hagafell, as indicated by seismic activity and geophysical modelling results.

The likelihood of an eruption remains high. Monitoring continues for signs of shallowing seismicity and sudden crustal movements, which could be precursors to magma breaking its way to the surface. At the time of writing, no such signs had been observed.


Updated 15. November at 11:30 UTC

Since midnight, about 800 earthquakes have been measured, most of them in the middle of the magma dyke at Sundhnúk at a depth of about 3-5 km. Seismic activity has remained constant since 11th of November. The main monitoring focus on seismic activity remains in the area of ​​the dike and Grindavík.

Deformation measurements show continued deformation in the area. They are consistent with magma still flowing into the dyke. Part of the magma dyke seems to be solidifying, especially at the edges, but not at the magma inflow area, which is believed to be near Sundhnúk.

Measurements of sulfur dioxide (SO2) seem to show fluctuating degassing due to the magma dyke, but further measurements are needed for confirmation. Analysis of this data is currently underway in collaboration with the Chalmers University in Sweden.

The fiber optic cable of HS Orka, that runs from Svartsengi west of Þorbjörn to Arfadalsvík is beeing used as a continuous seismic measuring line with high sensitivity. This is a new technology that has developed in recent years and is now used as additional measurements in collaboration with HS Orku and ETH in Switzerland.

Overall, the situation seems to be unchanged since yesterday. The probability of an eruption is still considered high. In the event of an eruption, the most likely location is at the magma dyke.


Updated 14. November at 19:20 UTC

Earlier this week, IMO specialists installed two DOAS remote sensing instruments on Húsafell. These instruments can measure the presence and the amount of SO2 in the atmosphere. One of the DOAS instruments detected SO2 yesterday and today at the newly formed graben, located between Sundhnúkagígar and Grindavík. Because of the low amount of daylight, the measurements can be imprecise, and it took time to review the data and interpret it. In the last two days, eastern winds have been prevalent in the area, so it cannot be ruled out that recent strong seismicity has caused the release of SO2 from beneath Fagardalsfjall, as magma at that location has not solidified yet since the eruption in July 2023.

It is hard to estimate the depth from which the SO2 is being released as the process is influenced by magma pressure. However, it is thought that the magma needs to be in the upper hundred meters of the crust in order for SO2 to be released. This is one of the reasons why the DOAS instruments have been sited close to Grindavík.

DOAS (Differential Optical Absorption Spectrometer) is a tool that can detect sulfur dioxide in the atmosphere. The method relies on visible light, which travels through the atmosphere, hits a sensor in the measuring device, which is then analyzed for certain colors (wavelengths) that are missing from the spectrum. Sulfur dioxide absorbs certain wavelengths of light, which means that light hits the measuring instrument in a different way if SO2 is detected. The probe scans certain sectors of the sky, and it provides information on the concentration of sulfur dioxide within the area scanned. DOAS measurements need daylight to work, so operating such instruments in the wintertime in Iceland can be challenging.


Updated 14. November at 12:40 UTC

Since midnight, 14 November, over 700 earthquakes have been located along the orientation of the magma intrusion, the largest of which was M 3.1 near to Hagafell. Last night, 13 November, stress-triggered seismicity occurred close to Kleifarvatn, with the largest earthquake registering M 3.8 at 21:09 UTC. Today, most earthquakes are occurring along the magma intrusion, with the majority being micro-earthquakes, commonly at focal depths of 3 to 5 km.

Deformation measurements, including high-resolution aerial observations, satellite radar imagery, and ground-based GPS observations reveal continued, ongoing ground movements due to the ongoing formation of the magma intrusion. These results are consistent with continued, albeit much lower magma inflow to the region of the intrusion.

Between 12 and 13 November, the inflow is estimated at 75 m3 / s, and the average depth to the top of the magma intrusion is thought to be around 800 m. The inflow and depth estimates are derived from model-based calculations, and they are subject to uncertainty.

Throughout this period of volcanic unrest, the focus has been continuous monitoring of seismicity and ground deformation in the Grindavík – Svartsengi region. To further our monitoring capabilities, we have installed additional GPS stations in and around Grindavík. The latest measurements from these stations show that the graben-like formation is still forming and mechanically active. Furthermore, to increase our ability to warn of an eruption, we have installed ground-based SO2 detectors that overlook Grindavík and south of Sundhnúkur.

In summary, the likelihood of an eruption remains high. If an eruption occurs, the most likely location with be along the orientation of the magma intrusion, beginning as a fissure eruption.


Updated 13. November at 16:20 UTC

 

Seismicity along the magma intrusion continues, although the size and intensity of the activity is decreasing. Since midnight today, 13 November, around 900 earthquakes have been detected. The seismic activity is concentrated on the region of the intrusion, between Sundhnúkur and Grindavík at a depth of about 2–5 km.

Decreasing rates of ground deformation are seen in GPS data from Grindavík. Satellite radar results show a graben-like formation that cuts through part of Grindavík. This feature was first identified by IMO in satellite radar imagery early on 11 November.

Bylgjuvixlm-13-nov-michelle

 

This ascending COSMO-SkyMed (CSK) interferogram covers the time period 3-11 November and shows an extensive deformation field related to the dike intrusion that began on the afternoon of the 10 November within the Reykjanes-Svartsengi volcanic system. This CSK interferogram and the previous (spanning 2-10 November) supported the difficult decision made by Civil Protection to evacuate the town of Grindavík late Friday evening. It also enabled modelling of the dimensions of the dike intrusion (on the 11 November), which provided a median dike length of 15 km and top depth of less than 1 km below the surface. The imagery shows over 1-m of ground displacement in the western part of Grindavík, caused by the propagation of the magma intrusion. From geodetical modelling results, we infer that (as of 12 November) the greatest area of magma upwelling is sourced close to Sundhnúkur, 3.5 km north-northeast of Grindavík.

New geodetic modelling is currently being undertaken, using an ICEYE interferogram and GNSS observations spanning the last 24-hours, to better assess the ongoing activity and provide an estimate of the current magma inflow rates.

According to our latest estimates, the volcanic hazard assessment in and around Grindavík is unchanged from 12 November. All monitoring systems are being monitored closely in real-time, especially near Grindavík, for any indications of sudden change. The natural hazards monitoring team at IMO is operating at maximum surveillance while the Department of Civil Protection and Emergency Management coordinates short-term, temporary access to Grindavík today, 13 November.

13-nov-enska-blar-litur

Estimate of the vertical displacements caused by the dike during its initial propagation from Friday afternoon to Saturday morning. The displacements were estimated by combining ICEYE and COSMO-SkyMed pixel offset tracking results.


Updated 12. November at 12:30 UTC

 

Since the morning of November 11th, seismic activity related to the magma intrusion remains fairly constant. Since midnight November 12th, around 1000 earthquakes have been recorded within the dyke, and all of them have been below M3.0 in magnitude. The most seismic activity has been located in the region north of Grindavík. Most of the earthquakes are at a depth of 3-5 km corresponding to the lower part of the dyke intrusion.

GPS measurements covering the past 24 hours show that deformation associated with the dyke intrusion that formed on Friday, November 10th has slowed. This can be an indication that magma is moving closer to the surface, new models will be run as soon as new data comes in to update the model.

It was a joint assessment from the meeting, based on the latest data, that there is scope for temporary measures under the control of the Department of Civil Protection and Emergency Management to collect necessities for the residents and attend to urgent errands in Grindavík and the surrounding area. During such operations, it is necessary to increase the vigilance of the area through additional monitoring with the aim of improving the detection of magma reaching the surface. It was the opinion of the scientists that it would be advisable to start these operations immediately, as uncertainty about the progress of the event grows as the day progresses. The final decision on whether these actions will be taken, and their implementation is in the hands of public safety and the Police Chief in Suðurnes.

In light of this joint assessment has the Police Chief in Suðurnes decided to allow inhabitant to part of restricted area in Þorkötlustaðahverfi and it is only to retrieve vital items, pets and livestock. This will be organised and controlled operation by the Police. This permission only applies to Þorkötlustaðahverfi. Note, special operation is ongoing to pick up all horses in the area north of Austurver.  

 

 

This news has been updated since the latest information from the Police Chief in Suðurnes.

Updated 11. November at 18:30 UTC

At 18:00 today, 11 November, a status meeting concluded between scientists at the Icelandic Meteorological Office, the University of Iceland, and the Department of Civil Protection and Emergency Management. The purpose of the meeting was to discuss the latest measurements of seismicity and ground deformation in the region of Grindavík, in addition to reviewing the latest geophysical models and hazard assessments. From combined assessments of satellite radar imagery, ground-based GPS measurements, and seismicity, it was concluded that the ongoing dike intrusion represents a serious volcanic hazard. 

From geophysical models of the dike intrusion, it is estimated that the intrusion is propagating upwards slowly, with magma thought to be 800 m beneath the surface. The exact location of a possible eruption site is unknown, but the 15-km length and orientation of the dike gives a good indication of possible sources. The overall assessment from the status meeting was that the likelihood of a volcanic eruption is high, and that an eruption could be possible on a timescale of just days. Based on the extent of the dike, magma could emerge from its southern, just outside of Grindavik. Therefore, the likelihood of a submarine eruption has also increased, so preparations must be made for the possibility of explosive activity. A hazard area has been defined based on the location of the dike, as shown in the map.

Kort-ragnar-enska-11-nov

Status map showing the location of the dike intrusion based on combined satellite radar imagery, GPS measurements, and geophysical modelling.

Updated 11. November at 12:00pm

 

Since midnight, around 800 earthquakes have been measured in the region where the magma intrusion is occurring. The earthquake activity has diminished slightly in the past hours, but it remains high. Most of the recent earthquakes have occurred close to Grindavík, where the southwest end of the magmatic dyke is estimated to be located.

Analysis of the earthquakes from today and yesterday is ongoing. The goal of this work is to better understand the evolution of the magma intrusion. Presently, the data indicates that the magma intrusion extends from Stóra-Skógsfell in the north to Grindavík in the south, where it extends beneath the sea. In accordance with the latest preliminary models, using the most recent satellite data acquired last night, the shallowest depth of the top of the magma intrusion north of Grindavík is 1.5 km. Joint interpretation of the ground and satellite measurements indicate that the size of the magma intrusion and the rate at which it is moving are several times larger than have been measured previously on the Reykjanes Peninsula. Our assessment is that an eruption, if it were to occur, will originate from the northern side of the magma intrusion. This means that there is a greater likelihood of an eruption beginning close to Sundhnjúkagígur.

Scientists are meeting regularly to interpret the data and update the latest models and hazard assessments. A meeting for journalists will be held at 12:00 at the Department of Civil Protection and Emergency Management. The current conditions and future scenarios will be discussed.

The likelihood of a volcanic eruption occurring in the near future is deemed considerable.

 

Skjalftavirkni_1011_1111

Reviewed earthquakes since 9pm last night.

Updated 10. November at 11:30pm

 

Significant changes have occurred in the seismic activity measured near Sundhnjúkagígar north of Grindavík and deformation observed in the Reykjanes Peninsula this afternoon. The seismic activity has moved south towards Grindavík. Based on how the seismic activity has evolved since 6 PM today, along with results from GPS measurements, there is a likelihood that a magma intrusion has extended beneath Grindavík. In light of this outcome, the police chief in Suðurnes, in cooperation with the Civil Protection Authorities, has decided to evacuate Grindavík. An emergency level of civil protection is now in effect. This is not an emergency evacuation. Residents of Grindavík are advised to proceed with caution.

At this stage, it is not possible to determine exactly whether and where magma might reach the surface. There are indications that a considerable amount of magma is moving in an area extending from Sundhnjúkagígum in the north towards Grindavík. The amount of magma involved is significantly more than what was observed in the largest magma intrusions associated with the eruptions at Fagradalsfjall. Further data is being collected to calculate models that provide a more accurate picture of the magma intrusion. It is currently not possible to say when this work will be completed.


 

Updated 10. November at 8pm

 

The seismic activity currently measured at Sundhnjúkagígar occurs within an area about 3 km northeast of Grindavík. The shallowest earthquakes measured now are at a depth of about 3-3.5 km.

The signs that can be seen now at Sundhnjúkagígar are similar to those seen on the eve of the first eruption at Fagradalsfjall in 2021 and are very similar to the seismic activity that was measured about a month before that eruption. The most likely scenario now, taking into account the activity that culminated in the onset of the March 19th 2021, is that it will take several days (rather than hours) for magma to reach the surface.  

Samsett-mynd-10-nov

 

Earthquakes on the 10th of November (until 6:48pm). The Icelandic Meteorological Office’s seismic network is shown with triangles. Four seismic stations surrounding the current seismic activity have been showing a large increase in tremor since 3pm.

Updated 10. November at 6:30pm

 

The National Commissioner of the Icelandic Police, in consultation with the Police Commissioner of Suðurnes, has declared a Civil Protection Alert Phase due to the intense earthquake swarm that commenced 3pm today at Sundhnjúkagígar, north of Grindavík. There is the possibility for larger earthquakes than have been experienced thus far, and this sequence of events could lead to an eruption. The Civil Protection Alert Phase means that the risk is increasing, and measures are being taken to ensure the utmost safety of those who live/stay in the area. This is done by increasing precautions in the relevant area.

The Aviation Color Code has been elevated to orange (heightened unrest with increased likelihood of eruption). IMO is closely monitoring the situation. Residents are encouraged to follow the information provided on Almannavarnir.


 

Updated 10. November at 2pm

 

Earlier today, at 12:44, an earthquake of magnitude 4.1 occurred near Sýlingarfell, west of Sundhnjúkagígar. The craters are about 2-3 km northeast of Grindavík. A dense swarm of earthquakes began around 07:00 this morning in the same area, and nearly 800 quakes have been recorded since midnight, including 9 greater than magnitude 3. The depth of the earthquakes is about 5 km. Such earthquake swarms have previously been recorded in this area. It cannot be ruled out that the seismic activity near Sundhnjúkagígar is due to magma movements at depth.

Magma accumulation continues near Þorbjörn at the same depth and at a similar rate as before. It is accompanied by swarm-like seismic activity, as was noticed yesterday and this morning. While magma accumulation continues, ongoing seismic activity can be expected due to stress release in the area. Earthquakes up to magnitude M5.5 can be expected in such swarms, and the seismic activity may shift between areas. At this stage, there are no indications that magma is forcing its way to the surface.

Yfirfarnir-skjalftar-10-nov

 

Reviewed earthquakes since midnight

Updated 9. November at 12:20pm

 

Around 1400 earthquakes have been recorded in the last 24 hours. Seismic activity increased from midnight, and the SIL seismic network has detected seven earthquakes above M4.0 since then. The largest earthquake measured M4.8 at 12:46am. It was located west of Þorbjörn. It is the largest earthquake since the activity began on October 25th. Seven earthquakes M4.0 or larger in size were measured in the area from Eldvörp to the area east of Sýlingarfell. While the accumulation of magma continues, seismic activity can be expected on the Reykjavík Peninsula because the magma intrusion causes increased tension in the area.

According to GPS data at midnight, uplift continues in the area. The GPS data is being reviewed in relation to the seismic activity tonight. Since the beginning of the inflation until today, the uplift has been fairly even, although an acceleration of the process has been observed between days. The seismic activity last night and this morning is an example of this episodic seismic activity that can be expected while magma accumulation is in progress. The fact that there are now larger earthquakes than before in the area does not necessarily mean an increased rate of magma accumulation.

9-nov-mynd

 

Reviewed earthquakes since midnight last night

Updated 8. November at 2:40pm

 

Approximately 1200 earthquakes have been measured in the last 24 hours, most of them in the area between Þorbjörn and Sýlingafell, similar to the day before. The largest earthquake was M3.4 at 12:31am last night, just south of Þorbjörn. The seismic activity continues at the same depth as before. It is likely that seismic activity will continue, and be episodic in intensity, while magma accumulation is ongoing. 

Uplift continues at a similar rate as before according to Satellite and GNSS data. Interferogram (InSAR) for the period 28th of October – 6th of November showing near-vertical motion confirms this, but it also shows offsets due to fault movements associated with the seismic activity. Updated models based on the same data estimate that magma continues to accumulate in a horizontal sill at a depth of about 5 km and since the beginning of the inflation event (October 27th) the average inflow is estimated about 5 m3/s (uncertainty is ±2 m3/s)

Bylgjuvixlm-8-nov-uppfaerd

 

Interferogram (InSAR) for the period 28th of October – 6th of November shows that deformation in that period is around 7 cm. SW of Mt. Þorbjörn is an offset in the deformation signal caused by fault movements by earthquakes.

Updated 7. November at 1:30pm

 

There have been around 900 earthquakes in the last 24 hours, most of them in the area between Þorbjörn and Sýlingafell. The largest earthquake was M2.9 and occurred around 7 am this morning. The seismic activity remains at the same depth as before.

According to satellite data processed around 5 pm yesterday and covers the period between November 4-6, confirms that uplift continues around Þorbjörn. The same data shows no signs of magma accumulation in Eldvörp or near Sýlingarfell, east of Svartsengi where seismic activity has been measued in recent days.

Magma accumulation continues at a depth of around 5 km in the are NW of Þorbjörn. If October 27th is considered the starting day of the inflation event until today, the rate of uplift has been fairly constant, although an acceleration of the process has been observed between days. It is likely that seismic activity will continue, and be episodic in intensity, while magma accumulation is ongoing.  

Yfirfarnir-skjalftar-7-nov

 

Reviewed earthquake locations since 6th of November and today until noon.

Updated 6. November at 1:15pm

 

In the last 24 hours around 1300 earthquakes have been detected on the Reykjanes peninsula, of which three earthquakes were above M3. The largest earthquake was M3.6 this morning and located 3 km NE of Mt. Þorbjörn.

Deformation data shows that uplift continues in the area and there are indications on GNSS observations of an increase in inflation rates since 3rd of November. Since the start of the inflation, the uplift at the GNSS station at Mt. Þorbjörn has reached 7 cm. The deformation is caused by a sill-type intrusion at around 5 km depth. Modelling, based on data since 27th of October, indicates that the volume change associated with this inflation event has reached almost two times the volume change associated with the four previous inflation events in the same area between 2020-2022. Inflow of magma/magmatic fluids into the sill-type body is estimated at approximately 7 m3/s which is about four times greater than the highest inflow estimated during previous inflation events here.

While the inflation  continues, increased seismicity in the area can be expected from additional stress changes  induced within the crust. 

6-nov-2023

Data from GNSS station at Mt. Þorbjörn. The graph at the bottom shows the uplift.

 

Updated 4. November at 11:30pm

 

After 17:30 yesterday, seismic activity decreased considerably. In the last 12 hours, about 900 earthquakes have been detected, all under M3.0. The activity after midnight as mainly been located at Sundhnjúkagígar – NE of Þorbjörn, as well as west of Eldvörp.

Seismicity has decreased considerably since yesterday, but the development of earthquake magnitudes, number of earthquakes and their location is comparable to the development previously seen related to magma accumulation in the vicinity of Þorbjörn.

The latest deformation data shows that uplift continues in the area. This uplift is thought to be due to magma accumulation NW of Þorbjörn at 4-5 km depth. While that magma accumulation continues, increased seismicity in the area can be expected from increased stresses in the crust. Rockfall can occur following large earthquakes, so caution should be taken by steep slopes.

The Icelandic Meteorological Office continues to monitor the area closely and to meet with the Civil protection agency to discuss the situation. Signs of magma coming towards the surface would appear as increased, shallower seismicity and rapid crustal deformation at the surface as well as volcanic tremor, which is a high rate of many small earthquakes. At the moment no clear signs can be seen of any of this, but the situation can change on short notice.

Virkni_04112023

Earthquakes (circles) with magnitude over 1.5, from midnight on 3 November until 10:45 on the 4 November. The colour bar to the left shows the time of the earthquakes and the size of the circles represents the relative size of the events. Locations of seismic stations (triangles) and GPS deformation stations (squares) are also shown.


 

Updated 3. November at 3pm

An earthquake of magnitude 4.3 was detected at 1:14 pm, today between Þorbjörn and Sýlingarfell. Another earthquake of magnitude 3.5 was detected at 2:01 pm in Þorbjörn. These earthquakes are thought to be due to continuing stress in the crust from magma accumulation undir Þorbjörn mountain. No volcanic tremor has been detected and the area is still being closely monitored.

Updated 3. November at 1:50pm

 

According to measurements from 11:00 am today, the uplift centered northwest of Þorbjörn continues. The uplift is caused by a magma intrusion at a depth of about 4 km. Seismic activity continues on the Reykjanes peninsula due to crustal stress changes caused by the intrusion. An increase in earthquake activity was detected after midnight and into the morning. Since midnight, around 1.000 earthquakes have been recorded in the area, with two being above M3.0 and two above M4.0. The biggest earthquake of the current swarm was measured at 8:06 am and was 4.3 in size. The biggest earthquakes last night seem to line up in a north-south direction west of Þorbjörn. This is happening on previously known fissures, where tension has been accumulating associated with plate tectonics and may curl due to tension from intrusions.

There are currently no clear signs of magma moving closer to the surface. Signs that magma is making its way to the surface would appear in shallower seismic activity and increasing tremor, which is a high frequency of small earthquakes. At the same time, sudden deformation of the surface should be measured with GPS measurements. The development of this event is closely monitored, as the course of events can change with very little notice.   

Model calculations show that the intrusion is located northwest of Þorbjörn, as shown in the accompanying image.  The most recent seismic activity has been over the intrusion itself. The earthquakes measured at Eldvörp and east of Grindavík road are due to tension from the magma intrusion by Þorbjörn, rather than signs of magma movements in those areas.

Ragnar-enska-3-nov

 

 

Approximate center of magma intrusion according to model calculations based on GPS and satellite images together with seismic activity from November 2nd at 8pm to November 3rd at 12pm larger that M1.0 in size. The model assumes a box-shaped intrusion, but its length and width are subject to quite a bit of uncertainty. The model will be frequently updated with the newest data once aquired, and the size and shape of the intrusion might change considerably, so there is quite some uncertainty to the model.


 

Updated 2. November at 3pm

 

GPS data from the last 24 hours indicate that uplift continues at a similar rate in the area northwest of Mt. Þorbjörn. Earthquake activity has been quite stable, but yesterday around 800 earthquakes were recorded in the area around Þorbjörn, and the largest was M3.7 at 12:56 am. Since midnight today, around 400 earthquakes have been recorded in the area, the largest measuring M2.8 at 9:51 am. More detailed analysis of recent GPS data confirms that a magma intrusion is forming at a depth of 4-5 km under the area northwest of Þorbjörn.  

It is important to note that seismic activity is will likely continue northwest of Þorbjörn, and earthquakes over M4.0 could be found in populated areas. Triggered seismic activity can also be expected in the coming days because the magma intrusion causes increased tension in the area. Rockfall can occur following strong earthquakes, so it is important to be cautious on steep slopes.  

2-nov

 

Reviewed earthquakes from midnight November 1st until noon November 2nd.

Updated 1. November at 12:20pm

 

On 25 October, an intense earthquake swarm began near Svartsengi, north of Grindavík on the Reykjanes Peninsula. So far, over 10,500 earthquakes have been detected in the swarm, with over 26 earthquakes exceeding magnitude three, the largest of which was magnitude 4.5 on 25 October at 08:18 UTC.

The latest satellite radar image, acquired late on 31 October, reveals 5 to 6 cm of ground movements over 12 days, centered just northwest of Mt. Þorbjörn. The same displacement signal is seen in continuous GPS measurements from stations in the region, beginning on 27 October. The latest GPS results from 1 November indicate that ground displacements continue in the region. Combining seismic, geodetic, and satellite-based observations, we infer that a volcanic intrusion is located at about 4 km depth just northwest of Mt. Þorbjörn. Presently, there are no indications that the volcanic intrusion is becoming shallower. We expect that seismicity will continue northwest of Mt. Þorbjörn, and this could include felt earthquakes exceeding magnitude four. Triggered earthquake activity is also possible in the coming days due to stress increases caused by the intrusion. This is a likely explanation for the ongoing seismic activity detected west of Þorbjörn in Eldvörp on 1 November. Triggered seismicity is also possible due to the long-term effects of magma accumulation beneath Fagradalsfjall.

Satellitbaseret InSAR-billede af Reykjanes-halvøen, der strækker sig fra 19. til 31. oktober. Dette billede giver et indblik i jordens deformation i løbet af de sidste 12 dage. Det største deformationssignal er centreret nordvest for bjerget Þorbjörn. Fra GPS-målinger er det tydeligt, at størstedelen af ​​centimeterskalaen jordforskydning er sket siden 27. oktober.

 

Opdateret 31. oktober kl. 17.00

 

I morges kl. 8.40 begyndte en jordskælvsværm ved Þorbjörn, som varede i næsten 2 timer og var usædvanlig intens. Det største jordskælv i sværmen målte M3,7. Aktivitetens centrum var lige øst for midten af ​​den stigning, der er observeret de seneste dage. Jordskælvenes dybde blev anslået til mellem 5 og 1,5 km dybde. Jordskælvsværmen er et tydeligt tegn på magmabevægelser i dybden. GPS-målinger understøtter fortolkningen, selvom stigningen, der startede for omkring fire dage siden, er aftaget. Tidligere i dag var der et møde med civilforsvaret og interessenter på Reykjanes-halvøen, hvor de seneste målinger og mulige scenarier og svar på det aktuelle scenarie blev diskuteret.

Situationen overvåges nøje

IMO følger udviklingen nøje og ser på, om mikroseismisk aktivitet stiger tættere på overfladen, hvilket kan være et tegn på, at magma bryder sig vej gennem jordskorpen. I øjeblikket er der ingen tegn på, at jordskælvsaktiviteten bliver mere lavvandet. Situationen kan dog hurtigt ændre sig, og det er ikke muligt at udelukke et scenarie, der involverer et lavaproducerende udbrud i området nordvest for Þorbjörn. Det er vigtigt at påpege, at magmabevægelser, svarende til dem, der observeres tæt på Þorbjörn, ofte forsvinder og ikke fører til et vulkanudbrud. Ikke desto mindre kunne langvarig riftning og øget (udløst) jordskælvsaktivitet i Svartsengi-området have skabt svagheder i skorpen, hvilket gør det lettere for magma at bevæge sig til lavere dybder.

THob_Skjalftavirkni_31102023

 

Gennemgået jordskælv fra midnat i dag.

Opdateret 30. oktober kl. 11.30

 

 

Sentinel-satellitdataene, der forventes at blive modtaget i går, er ikke ankommet endnu, men cGPS-dataene i området omkring Svartensgi og Þorbjörn viser, at deformationen stadig er i gang. Deformationshastigheden siden begyndelsen af ​​denne påtrængende begivenhed har været svagt faldende over tid. Foreløbige resultater fra deformationsmodeller tyder på, at den gennemsnitlige dybde, hvor den magmatiske instruktion finder sted, er omkring 4 km.

I løbet af de sidste 24 timer er omkring 1300 jordskælv automatisk blevet registreret på Reykjanes-halvøen. Det meste af denne seismicitet er placeret i en dybde mellem 2-4 km. Det største jordskælv havde en størrelsesorden M2,7 den 29. oktober kl. 11:40 UTC.

Forskere fra det islandske meteorologiske kontor foretager yderligere overflademålinger i området, herunder geokemiske observationer. Der opretholdes regelmæssig kommunikation mellem IMO, HS-Orka og Civilbeskyttelsen, mens denne uro fortsætter.

THOB_8hrap-30-okt

8-timers løsning til cGNSS THOB-stationen i Þorbjörn, der viser det seneste datapunkt opdateret kl. 08:00 UTC i dag


 

Opdateret 29. oktober kl. 14.00

 

De seneste cGPS-deformationsdata omkring Þorbjörn og Svartengi-området bekræfter, at deformationen, som startede 27. oktober, fortsætter. Som indledningsvis anført, er de igangværende deformationshastigheder højere end i tidligere hændelser, som fandt sted i et lignende område i 2020 og 2022. Samlet set har seismiciteten nord for Grindavík været faldende i løbet af det seneste døgn, og der er ingen væsentlige ændringer i jordskælvsdybderne. Det er dog vigtigt at understrege, at den nuværende deformation kan udløse fornyet seismicitet i området, som kunne mærkes af mennesker.

Nye satellitdata forventes at blive leveret senere i dag, og et nyt interferogram vil blive behandlet, så snart dataene er tilgængelige. Resultaterne vil give os mulighed for at identificere og fortolke de deformationsprocesser, der har fundet sted på halvøen i løbet af de seneste 12 dage. Vi forventede at offentliggøre resultaterne i morgen.

En episode med kompleks vulkan-tektonisk uro påvirker i øjeblikket Reykjanes-halvøen. Det fortolkes som et resultat af flere deformationskilder i dybden, som interagerer og påvirker et bredt område på tværs af halvøen.

THOB_8hrap-29-okt

8-timers løsning til cGNSS THOB-stationen i Þorbjörn, der viser det seneste datapunkt opdateret kl. 08:00 UTC i dag, den 29. oktober.

 

Opdateret 28. oktober kl. 13.30

 

De seneste cGPS-målinger, sammen med et nyligt erhvervet InSAR-billede over Reykjanes-halvøen, afslører et tydeligt tegn på jordløft, centreret omkring Svartsengi. Dette løftesignal begyndte på et tidspunkt den 27. oktober, og det afspejler en trykstigning, der sandsynligvis er forårsaget af en magmatisk indtrængen i dybden. Midten af ​​løftesignalet er omkring 1,5 km nordvest for Þorbjörn, tæt på Den Blå Lagune. I 2020 og 2022 blev lignende opløftningssignaler detekteret i samme område og med lignende geometri. Dette er nu den femte inflationsbegivenhed i området. Fra en indledende vurdering forekommer det igangværende opløftningssignal hurtigere end tidligere. I øjeblikket er der ingen indikationer på, at magma bevæger sig på lavere dybde. Situationen kan dog udvikle sig hurtigt. For eksempel er der sket betydelige fraktureringer i Svartsengi-området på grund af udløst seismicitet i de seneste dage. En sådan frakturering kunne gøre det muligt for magma at finde veje til mindre dybde.

Samlet set viser de seneste deformationsresultater fra Reykjanes-halvøen en kompleks, igangværende proces med magmabevægelser i jordskorpen. Disse processer påvirker et bredt område, herunder Fagradalsfjall (hvor langsigtet inflation fortsætter), øst for Festarfjall (hvor deformationen ser ud til at være stoppet), og – i de sidste 24 timer – viser et område tæt på Svartsengi inflation.

Den seismiske sværm, der begyndte den 25. oktober nord for Grindavík, har resulteret i over 7.000 jordskælv. Niveauet af jordskælv er reduceret betydeligt, selvom sværmen stadig er i gang, hvilket betyder, at der stadig er sandsynlighed for jordskælv.

Geophysical modelling is underway today to determine the depth and size of the uplift source close to Svartsengi. An additional satellite radar image will be available from Reykjanes Peninsula on 29 October. This image should provide an even closer insight into the recent magma movements and deformation pattens on the peninsula.

Insar-28-okt-nr-2

 

 

“Line-of-sight” (LOS) deformation measured by the ICEYE SAR satellite between the 26 October at 05:21 UTC and the 28 October at 05:21 UTC. Satellite data provided in collaboration with ICEYE (https://www.iceye.com/).


 

Updated 27th of October at 2pm

 

The ground-deformation signal detected since yesterday in the area East of Festarfjall is confirmed by the latest cGPS data. The horizontal displacement over the past few days is ~ 2 cm as seen at FEFC station and movement has now also been measured at another cGPS station located in Selatangar. A 1-day interferogram spanning 26 to  27 of October, does not reveal any significant changes in the area, but the signal at FEFC measured during this 24-hr period was smaller than 1 cm, likely too small to be detected by this interferogram.  cGPS stations in Grindavík and north of here show no significant changes.

The seismic swarm north of Grindavík continues with around 1000 earthquakes since midnight. A total of 5800 eqs have been recorded since the beginning of the activity. An earthquakes M4.0 was measured at 04:02 UTC on 27 October around 2 km north of Grindavík. The seismic activity is interpreted as the response of the crust to the stress changes induced by continued magmatic inflow at depth beneath the Fagradalsfjall volcanic system.

Gps-stod-27-okt

 

Displacement at cGNSS station FEFC east of Festarfjall. Blue vertical line marks the onset of a dike intrusion in July 2023 and the red line the start an eruption near Litli-Hrútur 10th of July 2023. Most recent data points show up movement and horizontal movement towards SE.

Kort-27-okt

cGNSS stations at Reykjanes Peninsula. Data from stations FEFC and STAN east of Festarfjall show movement in the last day.

Updated: 26th of October at 5pm

 

The seismic swarm that commenced on 24 October continues. Over 4,000 earthquakes have been recorded on the Reykjanes Peninsula, of which 14 had a magnitude exceeding M3. Most of the activity has occurred between Stóra-Skogafell and North-East of Eldvörp. Seismicity is located between 2 and 6 km depth, with the largest earthquake (M4.5) measured on 25 October at 08:18 UTC. Scientists at the Icelandic Meteorological Office (IMO) interpret the ongoing seismic activity as triggered by stress induced by the ongoing deformation at Fagradalsfjall, which began soon after the summer 2023 eruption. The ongoing seismic swarm is expected to continue for the coming days. In the longer-term, the continued accumulation of magma beneath Fagradalsfjall could cause further seismic swarms on the peninsula.

Jorddeformationsmålinger nær Svartsengi og Grindavík viser ingen ændringer relateret til den igangværende seismiske sværm nord for Grindavík. En enkelt GPS-station (FEFC), øst for Festarfjall, begynder at vise lokaliseret bevægelse i sydøstlig retning. Disse målinger kunne indikere tilstedeværelsen af ​​magma i dybden langs fortsættelsen af ​​digeindtrængninger, der er i nordøstlige retning mod sydvest, som er dannet under Fagradalsfjall siden 2021.

Personale fra IMO fortsætter med at overvåge de seismiske uroligheder nøje. I de kommende dage vil satellitdata blive brugt til bedre at vurdere den rumlige udstrækning af enhver jorddeformation. Målingerne vil også blive brugt til bedre at forstå igangværende geofysiske processer på Reykjanes-halvøen.

Kort-a-ensku-26102023

 

Gennemgået udløste jordskælv fra 20.-26. oktober.

Skrevet 25. oktober: 

I nat startede en intens jordskælvsværm nær Svartsengi, nord for Grindavík. Over 1000 jordskælv er blevet opdaget der siden midnat, og sværmen er stadig i gang. De største jordskælv, der er registreret, er M3.9 kl. 5.35 UTC og M4.5 kl. 8.18 UTC. Begge disse jordskælv opstod på omkring 5 km dybde. Seneste deformationsdata indsamlet fra flere stationer omkring Þorbjörn/Grindavík området viser ikke signifikante ændringer korreleret med den igangværende seismiske aktivitet. I lyset af de data, der i øjeblikket er tilgængelige, fortolkes denne seismicitet til at være sandsynligt udløst af stressændringer relateret til tidligere påtrængende aktivitet på halvøen. Der er i øjeblikket ingen indikationer på magmavandring under Þorbjörn/Grindavík-området, men situationen kan ændre sig når som helst, og den kan udvikle sig over kort tid fra timer til dage. Som rapporteret i september er en magmatisk indtrængen i gang under Fagradalsfjall.

 

Personale fra IMO fortsætter med at overvåge området tæt og fortolke de nyeste data, efterhånden som de bliver tilgængelige.

Usikkerhedsniveauet for Department of Civil Protection er blevet erklæret på grund af denne seismiske sværm.

Gps-mynd-fyrir-frett

 

 

8-timers løsning til cGNSS THOB-stationen i Þorbjörn, der viser det seneste datapunkt opdateret kl. 08:00 UTC i dag.

Mynd-3

Gennemgået jordskælvssteder fra midnat til middag den 25. oktober .

 

SjalfvirktAutomatiske lokaliseringer af jordskælv fra midnat til middag den 25. oktober .


 
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