Nearly 800 earthquakes were detected between midnight and 10.00am this morning by monitoring equipment on the Reykjanes peninsula. The strongest was a magnitude 4.9 earthquake around 1.30am that was felt across the Reykjanes peninsula and the Reykjavík capital area as well as West and South Iceland. The earthquakes are part of a swarm that began five days ago and will likely continue throughout the week. An Alert Phase declared by the Civil Protection Department is ongoing for the Reykjavík capital area, the Reykjanes peninsula, and Árnessýsla.
The largest earthquake in the swarm occurred last Wednesday, February 24, and measured M5.7. Another earthquake, which occurred at 8.07am on Saturday, February 27 measured M5.2. Yesterday, February 28, brought seven earthquakes that measured between M4.0 and M4.7. The earthquakes originate in an area roughly between Kleifarvatn lake and the town of Grindavík.
1/2 Swarm still ongoing, since February 24 the SIL system has detected over 10 000 earthquakes in the area. Around 30 earthquakes of M4 and greater have been recorded and around 200 above M3. Yesterday evening (Feb. 28) At 19:01 an earthquake around M4.7 about 1.5 km SW of Keili.
— Icelandic Meteorological Office – IMO (@Vedurstofan) March 1, 2021
Kristín Jónsdóttir, Earthquake Hazards Co-ordinator at the Icelandic Met Office, stated such powerful swarms are known to occur in the area at roughly 25-year intervals. So far, there is no sign the earthquakes are connected to volcanic activity. Kristín stated it was likely the activity would decrease this week, though it is not certain.
The public is advised to be cautious on steep slopes and avoid areas where rock falls or avalanches can occur. These areas include Kleifarvatn lake, Esja mountain, Ingólfsfjall, Bláfjöll, Hengill, Keilir, Helgafell, and Vifilsfell outdoor recreation areas. Information on earthquake preparedness in English is available on the Civil Protection Department’s website.