Around 14:30 local time on 12 March, a strong earthquake swarm began offshore near Reykjanestá.
The swarm was most intense in its initial hours, with approximately 50 to 60 earthquakes recorded. As the day progressed, the activity subsided but then surged again shortly before midnight when a M 3.5 earthquake occurred. During this renewed activity, the swarm shifted slightly westward.
So far, around 600 earthquakes have been detected in the area, including six with magnitudes exceeding M3. Some of these tremors were reportedly felt in populated areas, including Grindavík, located about 12 km east of the epicenter. The swarm’s behavior suggests that activity can fluctuate, decreasing at times before suddenly intensifying again. Since 2023, five similar earthquake swarms have occurred in this same region, with notable swarms also recorded in 2021 and 2022.
These earthquakes may be triggered by stress field changes on the Reykjanes Peninsula, potentially linked to the recent seismic activity and intrusions. However, deformation data from the past few days do not provide clear evidence that magma movement is driving the current seismicity. Scientists at the Icelandic Meteorological Office continue to closely monitor all measurements around Reykjanestá to determine the most likely cause of the ongoing activity.