Earthquake swarm shaking Tjörnes Fracture Zone, Iceland

An earthquake swarm that started in Tjörnes Fracture Zone on Saturday, March 23, 2019 is still ongoing and the number of earthquakes has increased on March 27, the Icelandic Met Office reported 22:40 UTC, March 27.

The quakes are located 6 km (3.7 miles) southwest of the town of Kópasker. A magnitude 4.2 earthquake was reported at 20:30 UTC on March 27, which is the largest earthquake in the swarm so far.

M3.3 took place in the same are 30 seconds later and was followed by M3.3 and M3.2 at 21:47 and 21:49 UTC, respectively.

IMO said it has received reports from people in the area that felt the largest earthquakes, adding that a number of smaller aftershocks are now being detected. 

Almost 500 earthquakes have been measured in the area on March 27 and in total, roughly 900 earthquakes since the swarm started March 23.

The office said earthquake swarms in this area are common.

The swarm continued into Thursday, March 28 with 216 earthquakes detected from midnight to 07:32, ~30 quakes per hour. The strongest was M3.8 at 05:48 UTC at a depth of 2.3 km (1.4 miles).

The offshore Tjörnes Fracture Zone is an oblique transform zone that separates the northern volcanic zone of Iceland from the Kolbeinsey Ridge, part of the Mid-Atlantic Ridge north of Iceland.

A submarine eruption was reported during 1867-1868 at the SE part of the fissure system off the northern coast of Iceland along the Manareyjar Ridge immediately north of Manareyjar Island.

Featured image credit: Google, TW