© Golli
The latest cGPS deformation data around the Þorbjörn and Svartengi area confirm that the deformation, which started 27 October, continues. As initially stated, the ongoing deformation rates are higher than in previous events which occurred in a similar area in 2020 and 2022. Overall, the seismicity north of Grindavík has been declining over the past 24 hours and there are no significant changes in earthquake depths. However, it is important to emphasise that the current deformation may trigger renewed seismicity in the area that could be felt by people.
New satellite data are expected to be delivered later today, and a new interferogram will be processed as soon as the data are available. The results will allow us to identify and interpret the deformation processes that have occurred on the peninsula over the past 12 days. We expected to publish the results tomorrow.
An episode of complex volcano-tectonic unrest is currently affecting the Reykjanes Peninsula. It is interpreted to result from multiple deformation sources at depth, which are interacting and affecting a wide area across the peninsula.
“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 28th of October at 1:30pm
The latest cGPS measurements, along with a newly acquired InSAR image over Reykjanes Peninsula, reveals a clear sign of ground uplift, centred around Svartsengi. This uplift signal began at some point on 27 October, and it reflects a pressure increase that is probably caused by a magmatic intrusion at depth. The centre of the uplift signal is around 1.5 km northwest of Þorbjörn, close to the Blue Lagoon. In 2020 and 2022, similar uplift signals were detected in the same area and with similar geometry. This is now the fifth inflation event in the area. From an initial assessment, the ongoing uplift signal is occurring more rapidly than before. Presently, there are no indications of magma moving at shallower depth. However, the situation may evolve rapidly. For instance, significant fracturing has occurred in the Svartsengi area due to triggered seismicity in recent days. Such fracturing could allow magma to find pathways to shallower depth.
Overall, the latest deformation results from the Reykjanes Peninsula show a complex, ongoing process of magma movements in the earth's crust. These processes are affecting a wide area, including Fagradalsfjall (where long-term inflation continues), east of Festarfjall (where the deformation seems to have stopped), and - in the last 24 hours - an area close to Svartsengi shows inflation.
The seismic swarm that began on 25 October north of Grindavík has resulted in over 7.000 earthquakes. The level of earthquake has reduced considerably, although the swarm is still ongoing, meaning that felt earthquakes are still likely.
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.
Reviewed triggered earthquakes from October 20-26th.
"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/).
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