Continued Uplift in Svartsengi
Update 6. May- Uplift in Svartsengi continues, although the rate has slowly decreased
- Based on the rate of magma accumulation in recent weeks, the likelihood of a new eruption increases as autumn approaches
- Seismic activity along the dike has decreased
- The hazard assessment map has been updated and remains valid until May 20, unless conditions change
Deformation data (GPS) show clear signs of ongoing uplift in Svartsengi, although its rate has slowed in recent weeks. Scientists have assessed when the likelihood of a new magma intrusion or eruption might increase. This assessment assumes that the same amount of magma must accumulate beneath Svartsengi as in previous events in the Sundhnúkur crater row. If the uplift continues at the same rate as today, the likelihood of a new dike or eruption is expected to increase as autumn approaches. However, if the rate of uplift, and thus the magma accumulation under Svartsengi, changes, it will affect this assessment.
Scientists at the Icelandic Meteorological Office are now revising the potential scenarios and are evaluating, among other things, the amount of magma beneath Svartsengi necessary to trigger a new dike or even an eruption.
Changes in uplift rate assessed over weeks rather than days
Deformation data showing uplift often fluctuate slightly from day to day, even if the underlying magma inflow is steady. These daily variations can be caused by weather, measurement errors, or other natural factors that have little impact on the overall picture. Looking only at short time periods may give a misleading impression of whether uplift is increasing or decreasing. Therefore, it is important to analyze trends over a week or longer to get a realistic view of what is happening. It is crucial to interpret these data in the context of longer-term trends rather than focusing on measurements from individual daily GPS measurements.
Seismic activity continues along the dike that was formed on April 1, but activity has decreased since the end of the eruption. On average, several dozen earthquakes have been recorded per day over the past two weeks.
The hazard assessment map has been updated and remains valid until May 20, unless changes occur. A new information update is also planned for May 20.
Update 22. April kl. 12:30 UTC
The rate of deformation at Svartsengi has decreased
Considerable micro-earthquake activity is still being recorded near the dike intrusion
The hazard assessment has been updated and is valid until May 6, assuming no changes
The Icelandic Meteorological Office continues to monitor the development of magma accumulation and assess possible scenarios based on the latest data.
The map shows reviewed earthquakes on the Reykjanes Peninsula over the past week. Most of the earthquakes were located near the magma intrusion that was formed on April 1st and in the western part of Fagradalsfjall. The color differences of the points indicate the timing of the earthquakes, with the reddish points marking earthquakes that happened in the past day and the blue ones about a week ago.
Micro-earthquake activity continues near the magma intrusion that formed on April 1, with an average of about one hundred earthquakes per day in the past week. Most of the earthquakes are below magnitude 1, with the largest one recorded at magnitude 1.7 during the past week. There was also some minor earthquake activity near Fagradalsfjall last weekend. Calm weather in recent days has allowed the monitoring network to detect even the smallest earthquakes that would otherwise likely not be recorded due to weather noise.
The hazard map has been updated and is valid until May 6th, assuming no changes.
News update 15. April
- The rate of deformation at Svartsengi has decreased
- Seismic activity over the dike intrusion is declining
- A new version of the hazard assessment map takes effect today, April 15
Minor seismic activity is still being recorded around the dike intrusion that formed on April 1, with dozens of earthquakes occurring daily in the area. The largest earthquake over the past week was a magnitude 3.3 on April 13, located over the northern part of the dike intrusion, about 4 km ENE of Keilir. Most of the earthquakes are under magnitude 2 and at depths of 2 to 6 km.
Uplift at Svartsengi continues, though the rate has slowed compared to last week. The current rate is about twice as fast as it was just before the last eruption, and is similar to the rate observed at the start of the current eruption cycle that began in 2024.
The Icelandic Meteorological Office continues to monitor the area, track magma accumulation, and assess possible scenarios based on the latest data. As long as magma continues to accumulate beneath Svartsengi, repeated magma intrusions and even eruptions along the Sundhnúkur crater row must be considered possible.
New hazard map covering a larger area
Today, a new version of a hazard map is published and distributed by the Icelandic Meteorological Office to inform and report on the level of hazard due to the ongoing unrest in the Reykjanes peninsula. This map replaces the previous hazard map that has been in use and published since November 2023, which showed hazard assessments for seven well-defined zones near the activity around the Sundhnúkur crater row.
The seven-zone map has been updated and issued 108 times since November 20, 2023. While it had its strengths, its limitations included difficulty in assessing hazards outside the defined zones.
Recent developments on the peninsula, where a magma intrusion formed and reached the northeastern part of the Svartsengi volcanic system on April 1, 2025, and an eruption that occurred west of the northernmost part of Fagradalsfjall in August 2024, highlight the need for a hazard assessment that covers a larger area.
A new map has therefore been developed to address the limitations of the previous version. This new approach is not only applicable to the Reykjanes Peninsula but also introduces a methodology that can be used for all other active volcanic systems in Iceland.
Layout
and presentation of the new hazard map, replacing the seven-zone map as of
April 15, 2025.
New features include: 1. Volcanic alert
level system (see blue box 1), expanded mapped hazard area (see blue box 2)
and target zones (see blue box 3). See further details in the
accompanying text.
The hazard map is based on three components
There are three major updates in the new map:
1. Volcanic Alert Level – This reflects the current status of the volcanic system and uses a four-tier color-coded scale from 0 (green) to 3 (red).
The alert level indicates the status of the volcanic system and determines how the hazard is assessed.
2. Mapped Hazards – The assessment is based on a combined evaluation of seven hazards that are present or may arise: 1) seismic activity, 2) sinkholes, 3) fault movements, 4) eruptive fissure, 5) lava flow, 6) tephra fallout, 7) gas pollution. Each location within the domain shows the cumulative level of hazard according to the volcano status. The shapes and sizes of these areas may change depending on the evaluated hazard at any given time.
3. Target Zones – Once the different hazards are
estimated, the averaged hazard level is calculated within pre-selected target
zones. For these zones, hazards contributing to the final hazard level are
listed and described. The size and shape of these target zones
remain fixed, even if their hazard levels may change with time.
