A seismic swarm began on October 19, 2019, in Öxarfjörður, Tjörnes Fracture Zone, North Iceland.
The swarm is located around 28 km (17 miles) WNW of Kópasker and Icelandic Met Office's (IMO) seismic network has detected roughly 500 earthquakes since it started, IMO reported 12:48 UTC on October 21.
The three largest earthquakes so far are M3.2 and occurred on October 20 at 11:03, M3.5 at 19:19 and M3.1 at 22:21 UTC. Magnitude of most of the earthquakes is between M1.0 and M2.0.
The IMO said it has received reports of the largest earthquakes being felt in nearby towns.
The seismic swarm is located on the Tjörnes Fracture Zone but an intense swarm occurred there in March this year.
In that swarm, around 2 600 earthquakes were measured during one week by IMO‘s seismic network. The largest earthquake in that swarm was M4.2. Then the earthquakes were located closer to Kópasker or around 6 km (3.7 miles) SW of the town.
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 from 1867 to 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: EMSC