More than 1,000 minor earthquakes have been picked up by sensors on the Tjörnes fissure zone in Northeast Iceland in the past few days. The earthquake swarm, which began on Tuesday and is still ongoing, is not considered likely to lead to more serious activity.
Lundey island seen from Tjörnes. Photo: Páll Stefánsson/Iceland Review.
“They occur in a very limited area at a depth of 9-13 km (6-8 miles). They are of a similar magnitude; the largest quakes measure around three. Such activity strongly indicates an intrusion, which is common in Iceland,” geophysicist Kristín Jónsdóttir at the Icelandic Met Office told visir.is.
Kristín explained that intrusion is caused by magma forcing its way to the earth’s crust. When asked whether similar earthquake swarms have occurred in this area before, Kristín responded: “It is rather unusual to have such dense activity right there. But the area is known for seismic activity.”