Minor earthquake swarm in Tjörnes Fracture Zone yesterday (30-August-2021)

Yesterday (30-August-2021) an small earthquake swarm took place east of Grímsey island in Tjörnes Fracture Zone. Two largest earthquakes had a magnitude of Mw3,2.

Earthquake swarm east of Grímsey island. Two green stars on top of each other.
Earthquakes east of Grímsey island. Copyright of this image belongs to Icelandic Met Office.

This earthquake swarm seems to have stopped for now. This area has frequent earthquake swarms and activity in this area of Tjörnes Fracture Zone might start again without warning.

Strong earthquake swarm ongoing on Reykjanes ridge

At midnight on 1-August-2021 an earthquake swarm seems to have started deep on the Reykjanes ridge. The current distance seems to be around 220 km away from Reykjavík or 190 km from Grindavík town. At this distance the location from Icelandic Met Office are not accurate. At the writing of this article the earthquake swarm seems to be ongoing.

Earthquake activity deep on the Reykjanes ridge. Many green stars are on the map that goes south along the Reykjanes ridge
The earthquake activity as it is shown on Icelandic Met Office map. Copyright of this image belongs to Icelandic Met Office.

Largest earthquake recorded at the writing of this article had a magnitude of Mw5,2 and the rest of the earthquakes have magnitude between Mw4,0 and Mw4,8. Overview of this earthquake activity can be found here on EMSC website. This links works as I publish this article. How long it is going to work I don’t know.

The current distance makes it impossible to know for sure what is going on at this location. The pattern of this earthquake activity suggests that this might be earthquake activity because of magma movement in the crust, but there is not any way to confirm this because of the location. Even if there is an eruption at this location it won’t make any difference to the surface of the ocean, since depth of the ocean at this location is more than 1 km. I don’t know the exact depth.