Iceland Mag

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Iceland Mag

Geology

Earthquake swarm on Reykjanes peninsula seems to be slowing down: 338 quakes since yesterday morning

By Staff

  • Gunnuhver geothermal area Reykjanes is extremely active, with a number of active volcanic systems, geothermal areas and regular earthquake swarms.

Yesterday‘s earthquake swarm at Fagradalsfjall mountain on Reykjanes peninsula, which started at 12 minutes past 7 in the morning, seems to be slowing down. A total of 338 quakes were detected in the swarm, with 12 quakes larger than 3 on the Richter scale. A second powerful swarm was detected in Katla volcano yesterday evening.

Read more: Why the constant earthquakes? Iceland is slowly being torn apart

Felt in West and South-West Iceland

Earthquakes Reykjanes 26.7
Tremling Earthquakes on Reykjanes peninsula in last 48 hours Photo/Icelandic Meteorological Office

The large swarm on Reykjanes peninsula, near Fagradalsfjall mountain east of the Blue Lagoon, which began early morning has continued today, although no major quakes larger than 3 have been measured since last night. The largest quake was 4.0 on the Richter scale, at 13:55 yesterday afternoon. The largest quakes were felt as far as Borgarnes town in West Iceland. Residents and travellers on Reykjanes felt many of the tremors.

The quakes have been at a significant depth of several kilometers in the area around Fagradalsfjall mountain, roughly 11 km (ca 7 mi) east of the Blue Lagoon.

Possibly the precursor to more activity
A professor of geophysics at the University of Iceland told the news site Vísir that there was nothing unusual about the quakes at Reykjanes, even though it was unusually large. Reykjanes is a part of the North Atlantic ridge which separates the North American and European tectonic plates. As the two plates drift in opposite directions significant amounts of energy build up in the crust, which is then released in earthquakes.

"It‘s a classic Reykjanes ridge earthquake swarm. These types of swarms come every now and then, one every 20-30 years, at least. Usually they come in clusters, with several swarms hitting over a period of several weeks or months."

He pointed out that a similar swarm hit in 1967-75. A second major swarm took place in 2000. If this swarm follows the previous pattern we can expect to see several more swarms i nthe coming days and weeks, he argued. 

Earthquakes Reykjanes 26.7

The intensity The time and size of all tremors on Reykjanes. The swarm seems to be slowing down. Photo/Icelandic Meteorological Office

 

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