Earthquake sequence at Kleifarvatn
Earthquakes on the Reykjanes peninsula
On 29 May at 13:10 an earthquake of magnitude 4.0 occurred under the northern part of Sveifluháls, close to lake Kleifarvatn on the Reykjanes peninsula (see map). It was widely felt in the capital area and in Akranes. Another magnitude 3.1 event was measured earlier the same day at 11:58 at the same location. Hypocenter depths of the earthquakes were around 3-4 km.
This earthquake sequence started in the morning around 10:00 and so far more than 100 events have been detected. Focal mechanisms of the largest events show normal faulting movements (vertical motion, see sketch below) in strike direction of the Sveifluháls mountain ridge. These mechanisms evidence that the earthquake sequence is located on the northeast-southwest striking fissures of the Krýsuvík volcanic system.
The main faulting systems on the Reykjanes peninsula are north-south striking tectonic faults with strike-slip movements (horizontal motions) and northeast-southwest striking fissures of the volcanic systems with normal faulting movements (vertical motions). Seismic sequences are frequently observed on both types of these fault systems. There are no signs of magma movements in the present sequence.
IMO continues to monitor the area closely. By late evening, the activity had significantly declined.