The earthquake swarm began around 7.00am on Sunday morning, with an earthquake of magnitude 3.5 measured at 8.00am. The activity calmed down around noon yesterday but began increasing again around 8.00pm. The largest earthquakes measured occurred just after that time, reaching magnitudes of 3.6 and 3.7. A third of magnitude 3.4 occurred 20 minutes later.
Three other quakes over 3.0 have occurred since 11.00pm last night. The seismic activity has continued into today, with earthquakes felt by residents in the capital region and as far away as Akranes.
No volcanic tremor detected
"The Reykjanes peninsula is a highly active geological area due to the rift between the Eurasian and North American continental plates," Elísabet Pálmadóttir, a Geohazard Specialist at the Icelandic Met Office, told Iceland Review. "The earthquake activity can be caused by volcanic or tectonic activity, even both. In this case, we believe it is due to tectonic stress that is being released through the earthquakes."
Elísabet stated that such swarms are known to go on for hours, days, and sometimes even weeks. "We see no signs of volcanic tremor, but we are following that very closely, especially since it is so close to inhabited areas."
Comment: Last month another earthquake swarm raised concerns for big volcanic eruption in Iceland.