The Seventh Eruption at the Sundhnúkar Crater Row Concludes
Clear Signs of Uplift in the Svartsengi Area
Updated 9. December at 15:10 UTC- The last activity in the crater was observed via webcams around 7 a.m. yesterday
- No activity was detected in the crater during today's drone flight
- The eruption lasted for 18 days
- The hazard assessment has been updated
The eruption east of Stóra-Skógfell has ended. This was confirmed today during a drone survey conducted by Civil Protection, which observed no eruptive activity in the area. The last glow in the crater was seen on webcams on the morning of December 8. The eruption began in the evening on November 20 and lasted for 18 days, and out of the seven eruptions that have occurred since December, 2023, it is the second-largest eruption by area.
As previously reported, ground uplift has resumed around Svartsengi and continued over the past few days. This indicates that magma accumulation has begun again in the reservoir beneath Svartsengi.
Displacement at the GPS station HS02, near Svartsengi, since November 11, 2023, in the north, east, and vertical directions (top, middle, bottom). The bottom curve shows uplift in millimeters, with yesterday's measurement (December 8) marked with a green dot. The red lines indicate the timing of the last seven eruptions (December 18, 2023; January 14, February 8, March 16, May 29, August 22, and November 20, 2024). The blue lines represent the timing of magma intrusions that did not result in eruptions (November 10, 2023 and March 2, 2024).
Updated 6 December at 15:00 UTC
GPS measurements and satellite data confirm that land uplift has resumed at Svartsengi
Gas pollution persists despite decreasing eruptive activity
The hazard assessment remains unchanged
Eruptive activity has been gradually decreasing in recent days. The reduced activity is visible on webcams, and volcanic tremor has been slowly declining over the past few days.
The active lava flow remains within the existing lava field, with little to no noticeable advancement beyond its margins.
The latest deformation data indicate that land uplift has resumed in Svartsengi. GPS measurements exhibit a gradual upward trend at several stations. The latest satellite images from ICEYE confirm the signals received from GPS instruments.
Image showing LOS (Line of Sight) displacement during the period from November 30 to December 4, 2024. The image is derived from ICEYE satellite data (InSAR). The red area indicates land uplift (~1 cm).
Gas pollution remains a concern despite diminished activity
Despite the reduced volcanic activity, gas pollution persists. The gas dispersion forecast predicts light variable winds today, making significant gas pollution unlikely in the area.
For the weekend, northerly winds are expected on Saturday, shifting to southerly winds on Sunday. Consequently, gas may be detected in Vogur on Sunday.
Visitors to the area are encouraged to monitor the gasdispersion forecast from the IMO and follow guidance regarding gas pollution at loftgadi.is.
Updated 3 December at 16:45 UTC
- The lava flow from the active crater has been steady in recent days.
- Advancement of the lava front is slow and does not threaten infrastructure.
- There is a balance between the inflow of magma to the reservoir beneath Svartsengi and the eruption of lava on the surface.
- The hazard assessment has been updated.
There has been insignificant change in the eruptive activity of the active vent in recent days, supported by seismic measurements. Lava continues to flow from the active crater, predominantly travelling southeast in the direction of Fagradalsfjall.
Minor changes have occurred at the lava front, but its overall advance has been slow. The crater continues to build up, increasing the risk of structural collapse. If this occurs, the direction of the lava flow could change, but infrastructure is not considered to be at risk due to the crater's location.
Deformation data indicate that there is a balance between the inflow of magma into the reservoir beneath Svartsengi and the outflow of lava at the surface from the active crater.
Gas pollution was measured at Húsafjall, east of Grindavík, over the weekend. The prevailing northerly winds carried gas southward from the eruption site.
Visitors in the area are advised to monitor the Icelandic Meteorological Office's gas dispersion forecasts and follow guidance on air quality at loftgadi.is.
Hazard
Assessment updated
The hazard assessment has been revised and updated based on the latest measurements and data. Key changes impact Zone 1 (Svartsengi), where the overall risk for the area has decreased from "considerable" (orange) to "moderate" (yellow). This change reflects the lack of lava flow toward Svartsengi in recent days. The hazard in Zone 6 has been lowered from "high" (red) to "considerable" (orange), as the threat from tephra fall is now considered minimal. Gas pollution remains a significant hazard in Zones 5 and 6, and an extreme hazard in Zone 3.
The hazard assessment is valid until December 10, provided no changes occur.
Updated 29 November at 17:00 UTC
- Evidence suggests magma continues to flow from depth into the magma chamber beneath Svartsengi.
- Harmful gas pollution is present on hiking paths near the eruption site.
- The hazard assessment has been updated.
The eruption at the Sundhnúkur Crater Row continued with steady activity overnight, similar to what has been observed in recent days, with minimal changes in eruption tremor. The lava flow from the active vent is predominantly moving southeast toward Fagradalsfjall.
Experts from the Icelandic Meteorological Office measured SO₂ emissions from the eruption on November 28. Their measurements indicated that this emission rate is 64–71 kg/s. Thus, gas pollution from the eruption is expected to persist in the coming days, potentially causing discomfort or health risks, especially on hiking paths near Fagradalsfjall and close to the eruption site. Weather forecasts for gas dispersal are provided bythe weather monitoring service.
Photo taken at 10:10 AM this morning from the IMO's webcam, installed yesterday on the western side of Fagradalsfjall, facing northwest towards the active vent and the lava river flowing southeast.
The second largest eruption at the Sundhnúkur Crater Row
Experts from the Icelandic Institute of Natural History conducted measurements and aerial surveys at the eruption site yesterday. Results indicate that the lava field from this eruption now covers 9.1 km², with a volume of approximately 47 million m³ and an average thickness exceeding 5 meters.
This eruption, which began nine days ago, is now the
second largest by volume among eruptions at the Sundhnúkur Crater Row since
December 2023.
A map showing the extent of the lava field from this eruption as it was on November 28 and the location of the active vent. It also shows the lava fields that have formed in the area during the series of recent eruptions that have occurred since December 2023 (lighter purple layers). The extent of the lava field is based on measurements by the Icelandic Institute of Natural History.
The lava field that formed during the August 22 to September 5 eruption, which lasted approximately 15 days, is the largest by volume, extruding approximately 61 million m³ of lava. The lava field formed during the eruption from May 29 to June 22 is the third largest, extruding around 45 million m³.
The upper graph shows the duration of eruptions on the Sundhnúkur Crater Row since December 2023 in days. The lower graph shows the volumes of the lava fields formed during these eruptions. Volumetric calculations are a result of collaboration among several parties and based on data from the Icelandic Institute of Natural History, Eflu, Verkís, Svarmi, and the Icelandic Meteorological Office.
Evidence that magma continues to flow from depth into the magma chamber beneath Svartsengi
Deformation measurements in the Svartsengi area show minimal daily changes, suggesting that magma inflow into the accumulation zone beneath Svartsengi remains consistent with the outflow from the eruption.
Based on measurements taken by the Icelandic Institute of Natural History, the average lava flow rate was approximately 11 m³/s from November 23 to 28. Based on SO₂ measurements from yesterday, the flow rate was estimated to be 7–8 m³/s. Current lava flow is roughly estimated to be 5–10 m³/s.
Hazard assessment updated
The Icelandic Meteorological Office has updated the hazard assessment for the eruption, valid until 3:00 PM on December 3, unless conditions change. Overall hazard levels remain unchanged in all areas. The hazard level for Zone 4 (Grindavík) remains unchanged, but there is one change for Zone 1 (Svartsengi), where the gas pollution hazard is now assessed as significant rather than very high.
Updated 28. November at 15:50 UTC
Lava is flowing mostly east and southeast
Activity remains steady, with the eruption continuing from a single vent
A significant decrease in the rate of subsidence around Svartsengi has been observed
Gas pollution is drifting southwest towards Grindavík. See gas dispersion forecast here
Eruptive activity has been steady over the last 24 hours, with lava now flowing predominantly east and southeast, towards and along the base of Fagradalsfjall. The lava field near Fagradalsfjall has expanded slightly but continues to thicken. Volcanic tremor has remained stable alongside eruptive activity in the vent. The rate of subsidence around Svartsengi has significantly reduced. However, because daily changes are minor, the trend of deformation measurements must be monitored over the next several days to determine whether uplift has resumed.
Photo captured this morning by a webcam at Litla-Skógfell. The camera faces southeast, showing the active vent on the right and the lava flow moving toward Fagradalsfjall on the left.
Northeasterly winds of 10-15 m/s are expected in Reykjanes today (Thursday), directing gas pollution southwest toward Grindavík. Winds are expected to calm this evening, increasing the likelihood of pollution being noticed widely across Reykjanes. Northeasterly winds will strengthen again tomorrow (Friday), with gas once more drifting toward Grindavík. No wildfires are anticipated in the eruption area.
Updated 27. November at 16:00 UTC
A single crater remains active, east of Stóra-Skógfell.
The lava flow continues to move eastward toward Fagradalsfjall.
Subsidence around Svartsengi has decreased, alongside diminishing volcanic activity.
Gas pollution may affect the capital region today. For further details, see the gas dispersion forecast.
Updated hazard assessment in effect until 29 November, assuming no changes.
The eruption has continued at a steady rate over the last 24 hours. Volcanic unrest remains stable, and the lava flow from the crater continues to move eastward toward Fagradalsfjall.
As volcanic activity decreases, subsidence around Svartsengi has slowed. Since day-to-day changes are minor, it is necessary to monitor the trend over several days to determine whether uplift has resumed. During the last two eruptions, it took about a week for uplift to become apparent after subsidence slowed. Thus, additional measurements over the next week will likely be needed to evaluate whether magma accumulation beneath Svartsengi will continue.
Displacements at GPS station SENG near Svartsengi over the past 90 days in the north, east, and vertical directions (top, middle, bottom). The lower graph shows vertical elevation changes in millimetres, with yesterday's (26 November) measurement marked by a green dot. The red line indicates the start of the eruption.
Gas
dispersion forecast
Our gas dispersion forecast estimates southwest winds today (Wednesday), carrying pollution north-eastward, possibly to the capital region. This evening, winds will shift to the west and later northwest, directing the pollution eastward and then south-eastward. Tomorrow (28 November), northeast winds are forecasted, which will carry pollution south-westward. Moss-fires at the eruption site are not expected. The gas dispersion forecast can be accessed here, and air quality information is available on the Environmental Agency's website.
Hazard assessment lowered for Svartsengi and Grindavík
The Icelandic Meteorological Office has issued an updated hazard assessment that is valid until 15:00 on 29 November, assuming no significant changes. Based on the eruption's development over the past few days and the gas dispersion forecast, the hazard assessment has been revised from the previous version.
The main changes involve Zone 1 (Svartsengi), where the overall hazard level is now assessed as considerable (amber) instead of high (red), and Zone 4 (Grindavík), where the overall hazard level has been downgraded from considerable (amber) to moderate (yellow).
In Zone 1 (Svartsengi), the risk of lava flow and gas pollution remains high, but the risk of tephra fall has been downgraded to moderate from considerable. For Zone 4 (Grindavík), the only change is that the risk of gas pollution is now assessed as "considerable," down from "very high." According to the gas dispersion forecast, there is a likelihood of gas pollution in Grindavík on 29 November.
Updated 26. November at 19:00 UTC
- One vent, located east of Stóra-Skógfell, remains active
- Lava is generally flowing eastward toward Fagradalsfjall
- Eruption tremor has remained stable since yesterday
- No uplift can be confirmed despite indications of changes in GNSS measurements
- The gasdispersion forecast is available here
Activity at the eruption site has been relatively stable since yesterday. Eruption tremor has remained consistent since yesterday, in conjunction with steady eruptive activity at the active vent overnight. Currently, activity is confined to the northernmost vent, located directly east of Stóra-Skógfell. The majority of lava from this vent is flowing eastward toward Fagradalsfjall.
It cannot be ruled out that lava may still be flowing beneath the solidified surface of the lava field that extended westward toward Svartsengi, despite no visible movements being observed in that part of the lava field overnight.
As volcanic activity diminishes, subsidence at Svartsengi is also decreasing. However, it cannot be definitively stated whether uplift has resumed, despite the most recent GNSS measurement points indicating changes in that direction. Since daily changes are so small, conclusions cannot be drawn from individual data points; instead, trends over a period of several days must be examined. In the last two eruptions, subsidence decreased gradually for over a week before uplift became measurable again. Therefore, it is likely that up to a week of additional measurements will be required before it can be determined whether uplift and magma accumulation beneath Svartsengi will resume.
A photo taken this morning by the Icelandic Meteorological Office's webcam, showing the active vent and the lava flow from it. The camera is located in Fagridal, just north of Fagradalsfjall.
The attached map, based on data from aerial surveys by the Icelandic Institute of Natural History and satellite data from Iceye, shows the extent of the lava field formed during this eruption, as it was at 02:49 yesterday, November 25.
Updated 25 November at 15:45 UTC
Activity has not decreased as quickly as it did in previous eruptions.
The rate of the flowing lava is comparable to the strongest eruptions at Fagradalsfjall.
The advancing lava flow may be exerting stress on the protective barriers at Svartsengi.
The hazard assessment remains unchanged.
Since yesterday in the early evening, volcanic tremor and visible activity from the eruption have further diminished, but the activity stabilized again after midnight. Nevertheless, the eruption remains quite powerful, and the activity has not decreased as quickly as it had in previous eruptions in the Sundhnúkur crater row. For comparison, the current lava flow is estimated to be on par with the most vigorous eruptions at Fagradalsfjall.
Text: RSAM graph showing the average amplitude of volcanic tremor (green and blue lines) since the eruption began on November 20. A sharp decline in tremor occurred on the morning of November 24, with a further decrease that evening. Comparing the tremor graph of this eruption to those of previous eruptions shows that activity in this eruption has not decreased as rapidly as it did during previous eruptions at the Sundhnúkur crater row.
The northernmost vent is the most active, with the main lava flow now extending eastward from it. Overnight, sporadic splashes of lava were observed above the rim of the southernmost vent, but no activity has been observed there today. Similarly, the middle vent, which was the most active during the first days of the eruption, experienced a significant decrease in activity yesterday, and no activity is visible today on live webcams.
The lava flow that has been travelling westward has slowed and cooled on the surface. However, lava may still continue to flow beneath this solidified crust toward the protective barriers near Svartsengi and the Blue Lagoon, though its advance has significantly slowed.
Experts from the Icelandic Institute of Natural History measured the lava field's spread on Saturday, about three days into the eruption. According to these measurements, the total volume of lava had reached about 43 million cubic meters, covering approximately 8.5 square kilometers. This is roughly 65% of the volume from the last eruption, which lasted 14 days.
Land continues to subside in Svartsengi, though at a slower rate compared to what was observed at the start of the eruption. It is still too early to determine whether magma accumulation will persist under Svartsengi. The flow of lava from eruptive vents needs to decrease further before any conclusions can be made about continued magma accumulation.
Important to Continue Monitoring Gas Pollution
Today, wind directions are shifting and becoming variable, meaning volcanic pollution could spread to the surrounding areas in the southwestern part of the country. See the gas dispersionforecast and real-time measurements on the Environment Agency'swebsite
Hazard Assessment Unchanged
The Icelandic Meteorological Office has issued an updated hazard assessment, which remains unchanged from the previous one. The hazard assessment is valid until 3 PM on Wednesday, November 27, barring any changes.
Updated 23 November 16:00 UTC
- Eruptive activity in three vents has been relatively steady since yesterday
- Seismic activity
remains low and land continues to subside at Svartsengi,
- The progression of lava flow near Svartsengi continues causing strain on the protective barriers
- Hazard assessment is valid until November 25th, unless stated otherwise.
- Link to the latest gas pollution forecast.
- Link to the current hazard map
Eruptive activity between Stóra-Skógfell and Sýlingarfell continues. Since yesterday, activity in three areas along the eruptive fissure have remained fairly stable.
Seismic activity remains low and land continues to subside at Svartsengi, consistent with significant magma outflow to the eruption.
The lava flow that crossed Grindavíkurvegur and the hot water pipeline to the west has continued travelling westward. The lava flow is causing some strain on the protective barriers around Svartsengi.
Gas dispersion forecast: Northeasterly and northerly wind today (Saturday) and tomorrow. Gas pollution will be advected to the southwest and south towards Grindavík and Svartsengi. Wildfires are not expected.
A screenshot from a webcam at Fagradalsfjall showing the activity at 3PM, 23 November.
Updated 22. November at 15:30 UTC
Eruptive activity in three vents has been relatively steady since yesterday
The progression of the lava flow slows significantly near Svartsengi
Land subsidence is occurring at Svartsengi
The hazard assessment has been updated, and it is valid until 25 November if conditions remain unchanged
Since yesterday, three areas along the eruptive fissure between Stóra-Skógfell and Sýlingarfell have been active. Activity in these areas remained fairly stable overnight, with the central vent showing the highest activity levels. Minor changes have been observed in volcanic tremor, consistent with stable activity in the eruption.
The lava is flowing primarily westward, originating from the central vent. Lava from the southern and northern parts of the fissure flows predominantly eastward but poses no threat to infrastructure. Near the protective barriers at Svartsengi, the lava's advance has slowed significantly. The lava tongue has encountered obstacles in the terrain at that location, spreading northward from the barriers and thickening. Compared to the initial phase of the eruption, the lava flow from the eruptive fissure has decreased considerably. However, a significant lava flow persists from the active craters, especially toward the west.
A photograph captured at 9:40 this morning via the Icelandic Meteorological Office's webcam in Fagradalsfjall. The camera faces southwest, showing three active areas along the eruptive fissure. Stóra-Skógfell can be seen on the right side of the image, while Þorbjörn appears in the background on the left.
Map showing the extent of the lava flow as of 1:38
AM, based on satellite imagery from ICEYE.
Land subsidence continues at Svartsengi
Land continues to subside at Svartsengi, consistent with significant magma outflow to the eruption. Approximately 10 million cubic meters of magma erupted during the first few hours, representing about half of the volume that had accumulated in the magma chamber since the last eruption. The pattern of subsidence at Svartsengi is similar to what was observed during the initial phases of the last two eruptions. Land subsidence is expected to continue as long as the injection of magma from the reservoir towards the eruptive fissure remains high.
Displacement at the GPS station SKSH (Skipastígshraun) in Svartsengi since mid-September, showing the north, east, and vertical component (top, middle, bottom). Measurements are taken every four hours, and the most recent reading from 8:00 AM this morning (22 November) indicates continued subsidence in the Svartsengi area. (Image courtesy of the University of Iceland.)
Hazard Assessment Updated
The hazard assessment has been updated and, barring any changes, is valid until 3:00 PM on 25 November. The main update is that the overall risk in Zone 4 (Grindavík) is now assessed to be considerable (orange).
According to measurements and visual inspections conducted yesterday by geological survey teams from ÍSOR, EFLA, and Verkís, there were no clear signs of new fractures or movements on existing fractures in Grindavík. As a result, fissure-related ground collapse has been downgraded as a hazard to the level it was before the present eruption began.
The possibility of lava flow and ashfall in Zone 4 (Grindavík) is assessed to be lower since no lava is moving toward the town. However, because of prevailing wind conditions in the coming days, gas pollution levels could be high in Grindavík. There are no changes to the overall hazard levels in other areas.
Gas Dispersion Forecast: Today, a northeasterly wind is expected, and tomorrow gas pollution will move southwest toward Grindavík and Svartsengi. No moss fires are anticipated. You can follow the gas dispersion forecast on our website, as well as monitor air quality on the Environmental Agency's website.
Updated 21. November at 16:45 UTC
- Lava has never flowed this far west before.
- Seismic activity and deformation remain minimal.
- Lava was advancing at a rate exceeding 100 meters per hour today.
- The hazard assessment will be updated tomorrow, November 22, if conditions remain unchanged.
Eruptive activity between Stóra-Skógfell and Sýlingarfell appears to be similar to that observed earlier this morning. Seismic activity and deformation at the eruption site remain very low.
Initial measurements suggest that the volume of magma that has travelled from Svartsengi towards the Sundhnúkur crater row is equivalent to half the volume that moved during the eruption on August 22. More detailed results are expected in the coming days.
The lava flow that crossed Grindavíkurvegur and the hot water pipeline to the west has continued travelling westward. By midday, lava reached the parking lot at the Blue Lagoon and continues to advance. The rate of advancement was measured to be over 100 meters per hour between 12:09 and 13:35.
This lava field has now extended farther west than any lava flow from previous eruptions. The accompanying images, captured by an IMO webcam positioned on Þorbjörn, show the lava's progression as of midday today and from 13:40 to 14:30.
Updated 21. November at 11:55 UTC
- Lava has flowed across the Grindavíkurvegur (Grindaík road)
- The eruptive fissure has shortened
- A lava front has reached the hot water pipeline, the Njarðvík Line
The eruption, which began at 23:14 on November 20, is ongoing. However, activity along the eruptive fissure has contracted by approximately 600 meters from its southern end, according to drone measurements conducted by the Special Forces of the National Police Commissioner. The most active area is now around the central part of the fissure, between Stóri-Skógfell and Sýlingarfell. Lava crossed the Grindavík road around 04:30 this morning. Shortly before 08:00, the lava front also reached the hot water pipeline, the Njarðvík Line.
Seismic activity decreased significantly shortly after the eruption began, and only a few minor earthquakes have been recorded since. Deformation was detected in the first few hours following the eruption but is now minimal in the vicinity of the fissure.
The weatherforcast shows that winds from the northeast today (Thursday) and tomorrow (Friday) will carry gas pollution southward and westward from the eruption site. Gas pollution is likely to affect Grindavík, Svartsengi, and Reykjanesbær. No moss fires are expected.
Satellite imagery shows the eruption plume drifting southward at 04:41 this morning, consisting primarily of SO2 gas. From the onset of the eruption until late at night, winds were northerly, shifting to easterly in the early morning hours today.
Hazard Assessment Updated
The Icelandic Meteorological Office (IMO) updated the hazard assessment last night (November 20), which is effective until 15:00 on November 22 unless conditions change. Hazard levels have been elevated in all zones except Zone 7. A very high hazard (purple) is in effect for Zone 3, where the eruption originates. Hazard levels for Zones 1, 4, and 6 have been raised to high (red).
- An eruption began between Stóra-Skógfell and Sýlingarfell at 11:14 PM on 20 November
- The first signs of the magma intrusion were detected on instruments at around 10:30 PM.
- The length of the eruptive fissure is estimated to be approximately 3 km, with its southern end located near Sýlingarfell.
- Gas emissions are being carried southward over Grindavík.
- Link to IMO's gas pollution forecast
Updated at 02:10
The activity in the eruption appears to have peaked. The fissure seems to have stopped expanding, and based on measurements from the Icelandic Meteorological Office, there are no indications that the activity will increase.
The length of the eruption fissure is estimated to be about 3 km. The lava flow is spreading both eastward and westward. At this point, the lava front is approximately 500 meters away from Grindavíkurvegur to the west.
This eruption is significantly smaller than the last eruption, which began on 22 August. The estimated lava flow rate at present is about 1,300 m³/s, compared to approximately 2,500 m³/s during the August eruption.
What stands out is that seismic activity did not start increasing in the weeks leading up to this eruption, as was observed in previous events. The amount of magma that had accumulated beneath Svartsengi was similar to the amount prior to the last eruption. However, the recent trend indicates that increasingly larger volumes of magma are required to trigger the next event. This suggests that the pattern observed in earlier eruptions may be changing.
(Photo: Civil Protection/Björn Oddsson)
Updated at 00:10
A small earthquake swarm began at around 10:30 PM on 20 November. This was followed by pressure changes at 10:37 PM in boreholes operated by HS Orka. Both independent measurements were a clear sign of the onset of a magma intrusion.
At 11:14 PM on 20 November, a volcanic fissure opened between Stóra-Skógfell and Sýlingarfell. The fissure extended north-eastward.
Initial reports of lava-flow indicate that lava is moving westward, south of Stóra-Skógfell. No lava flow has been observed heading southwards towards Grindavík.
Strong northerly winds in the area are directing gas emissions southward over Grindavík.
Map showing the estimated location of the eruptive fissure as of 11:40 PM on 20 November. The location is based on radar data from IMO's radar station at Keflavík Airport.
