Katla volcano (Iceland): magnitude 4.5 earthquake, strongest in decades

At least one earthquake of magnitude 4.5 occurred this morning under the volcano, the strongest recorded for Katla in recent decades. It was felt in nearby areas.
The Icelandic Met Office (IMO) reported two quakes, one at 01:47:02 local time at 3.8 km depth 8.1 km east of the summit (Goðabunga) followed 20 seconds later by another magnitude 4.5 quake at 0.1 km depth. Caution is required as these data are from automatic calculations which could actually in fact describe only one quake.
During the past 48 hours, IMO has detected 48 earthquakes - most of them tiny, but including 4 of magnitudes of 3 or higher - at shallow depths under Katla.
Whether these earthquakes are caused by magmatic activity - and thus could be a sign of a new eruption in preparation - or a result of gravitational adjustments (as ice melt during the summer changes the weight of the glacier) is currently unknown.

https://www.volcanodiscovery.com/katla/news/58874/Katla-volcano-Iceland-magnitude-45-earthquake-strongest-in-decades.html