Category: South Icelandic Seismic Zone

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Earthquake swarm in South Seismic Zone (SISZ)

This morning (7-July 2025) at 04:38 UTC an earthquake with magnitude of Mw3,4 took place in SISZ, close to a location called Árnes. More then a dozen smaller earthquakes followed the largest earthquake. There are no reports that this earthquake was felt, but its not impossible in the summer houses that are in this area.

Green star showing the largest and yellow dots showing smaller earthquakes.
Green star in the SISZ following the minor earthquake swarm. Copyright of this image belongs to Icelandic Met Office.

I don’t think this earthquake swarm is a sign of a large earthquake happening in SISZ. Since those often happen without much warning. This earthquake swarm has now stopped.

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Felt earthquake on South Icelandic Seismic zone

During the night of 30-December-2021 at 04:16 UTC an earthquake with magnitude of Mw3,0 was felt in Selfoss town and Hveragerði town. This earthquake was part of a swarm in the area that is ongoing at the writing of this article.

Green star on the far right on the map with few red dots, showing the earthquake activity in SISZ
Earthquake activity in SISZ. Copyright of this image belongs to Icelandic Met Office.

There are no volcanoes in this area so this is only a tectonic activity. It is not possible to know when this earthquake swarm ends. This might be a aftershock activity after the Mw6,3 earthquake in SISZ that took place in this location in the year 2008. I expect this earthquake swarm to continue to few more days to weeks and then just end quietly.