A series of earthquakes measuring around and below three points on the Richter scale were picked up by sensors west-southwest of the rocky islet Eldey off Reykjanes in southwest Iceland last night.

The view from Grímsey. Photo by Páll Stefánsson.

The largest of these earthquakes hit at 5:48 this morning. According to the Icelandic Meteorological Office’s seismic activity watch, such series occur in the area a few times a year. By 10 am it seemed to have passed, ruv.is reports.

Another series of earthquakes hit ten to 16 kilometers northeast of Iceland’s northernmost inhabited island, Grímsey, around 4 pm yesterday. Seismic activity is common in the area, visir.is reports.

The three largest quakes of between 2.0 and 2.3 on the Richter scale hit with a short intermission; the few aftershocks were weaker.

Meanwhile, more than 30 minor earthquakes caused by water from the operations of the Hellisheiðarvirkjun geothermal power plant being pumped into the ground hit Hveragerði in south Iceland last weekend. Four or five exceeded two points on the Richter scale.

“It is indisputable that the impact of the power plant in Hveragerði is much more extensive than what people had generally realized,” Mayor of Hveragerði Aldís Hafsteinsdóttir told Morgunblaðið.

CEO of Reykjavík Energy (OR) Bjarni Bjarnason stated that the pumping had been stable and that it would be interesting to determine what caused the quakes.

Víðir Reynisson at the National Commissioner of the Icelandic Police’s Civil Protection Department said Bjarni and Aldís had reviewed the matter jointly and it was not considered necessary to involve the Civil Protection Department.

“We contacted Aldís and discussed the matter when people were mostly concerned about it,” Víðir added, stating that the Civil Protection Department did not find that the manmade earthquakes pose a threat for Hveragerði residents; they are more of a nuisance.

However, there is a reaction plan in place for the region in case of larger earthquakes, Víðir pointed out. The region’s inhabitants are regularly subjected to sharp natural tremors; the last major earthquake hit in May 2008, causing considerable damage.

As for manmade earthquakes, Aldís said it is difficult for OR to announce them in advance as it is unclear when they will hit and how strong they will be.

She herself felt one of the earthquakes on Saturday. “I haven’t contacted OR because of it but our representative […] sent an enquiry to find out what was happening.”

Click here to read more about seismic activity in Iceland.

ESA