Updated: 11 November 2025
Key Points
Deformation Measurements
Uplift and magma accumulation beneath the Svartsengi region are continuing, though the rate has been gradually slowing. Looking at the history of the Sundhnúkur crater row, the risk of a new magma intrusion — and a resulting eruption — climbs sharply once accumulated magma approaches the volume seen before the previous event. Since the eruption in July, roughly 15 million cubic meters of magma have been recharged. That said, figures from past eruptions have ranged widely, anywhere from 12 to 31 million cubic meters.
Timing remains genuinely uncertain. As the rate of magma inflow appears to be easing off, the estimated window for potential activity has stretched further out. A graph of the data shows the lower volume threshold was crossed in early October. If current inflow rates hold, projections put the upper threshold — 23 million cubic meters, the average across the last five eruptions — somewhere around early February.
The model tracks magma accumulation at a depth of four kilometers beneath Svartsengi since July 17. Daily magma volume measurements are shown as black circles. The shaded area represents projected accumulation at a steady rate, while the red dashed line shows what the trend might look like if the inflow continues to slow.
Seismic Activity
Seismic activity near Grindavík and along the Sundhnúkur crater row has stayed relatively quiet. On most days, only a small number of microearthquakes are detected — typically around magnitude M1.
Activity near Krýsuvík
Deformation data from Krýsuvík points to a notable slowdown in the subsidence that began this summer. Tremor events, which had been occurring several times a day, have dropped from an average of around 250 per week to roughly 100–150 — the first sustained decline since summer.
Hazard Assessment
The hazard map has been revised and is set to remain unchanged until November 25. The Icelandic Meteorological Office is keeping a close eye on the situation and will issue updates if conditions change.
Updated: 28 October 2025
Key Points
- Uplift and magma accumulation beneath Svartsengi persist.
- The volume of magma expelled during each intrusion event has fluctuated between 12 and 31 million cubic meters.
- The exact timing of the next eruption remains highly uncertain.
- The current hazard assessment is unchanged, valid until November 11.
- Subsidence continues near Krýsuvík, although at a reduced pace.
Deformation Insights
Since the last eruption, around 14 million cubic meters of magma have built up beneath Svartsengi. Historical data from the Sundhnúkur crater row suggests the probability of another intrusion rises as this volume gets closer to what was released during the previous event.
Earthquake Activity
Seismic activity around Grindavík and the Sundhnúkur area remains low. Small earthquakes just above magnitude 1.0 are being recorded sporadically. A minor cluster of tremors appeared near the Sundhnúkur crater on October 11, but daily counts have mostly settled back to around five earthquakes.
Krýsuvík Activity
Earthquakes in Krýsuvík have been a daily occurrence. On October 22, two notable shakes were recorded near Kleifarvatn, measuring M3.1 and M3.6 — part of a day that saw over 120 earthquakes logged in the area. Subsidence is also ongoing; the Móhálsadalur GPS station has recorded around 55 mm of ground movement since early June, though the rate has since slowed.
Hazard Assessment Update
The Icelandic Meteorological Office is continuing to monitor conditions closely. The current hazard assessment stands until November 11, unless activity requires an earlier reassessment.
Continuous Monitoring
The Icelandic Meteorological Office runs round-the-clock monitoring of seismic activity, ground deformation, and gas emissions across Iceland. Updates are issued regularly to keep the public and relevant authorities informed of any changes in volcanic activity. For more detailed data, the Icelandic Volcano Web Portal at islenskeldfjoll.is covers Iceland’s geological developments in depth.
