Tjörnes Fracture Zone (north of Iceland) experiences strong earthquake swarm with magnitude 5.2 quake

Source: VolcanoDiscovery.com – By T, 10/21/12

A strong seismic swarm started shortly before midnight GMT in the Tjörnes Fracture Zone (TFZ) north of Iceland.

During the first 12 hours, about 300 quakes greater than magnitude 1 occurred at various depths ranging between 1 and 13 km, including 47 greater than magnitude 3. The largest was a widely felt M5.2 event in 10,8 km depth. Most quakes are located between the north coast of Iceland and the small island of Grimsey. A submarine volcano is known from a location north of Grimsey that erupted in 1372.

A weaker swarm yesterday around noon preceded the current one. Earthquakes, mostly of tectonic origin, are frequent in the TFZ, but since it is also near the volcanic rift zone, a magmatic component cannot be ruled out. At present, the nature of the quakes (purely seismic or magma intrusion) is not known.