Iceland Mag

4 Reykjavik

Iceland Mag

Geology

Manmade earthquakes east of the capital area

By Staff

  • Hellisheiði power plant Since 2012 scientists have stored around 170 tons of carbon dioxide underneath Hellisheiði in an attempt to turn carbon dioxide to stone. Photo/Valli

A series of earthquakes have been hitting the active volcano Hengill, which is located around 20 minutes drive east of Reykjavík.

However, it’s not the volcano, which is rumbling, the earthquake swarm is manmade. The swarm began last Friday with more that 300 quakes now registered. The majority are small, magnitude 1, a few around magnitude 2 and four around magnitude 3.

Iceland’s largest geothermal power plants are located in the Hengill area and the swarms are directly related to Reykjvík Energy (RE), the owner of the plants, pumping waste water back into the ground.

Since 2012 scientists have stored around 170 tons of carbon dioxide inside layers of basaltic rocks found 460 metres (1,500 feet) beneath the geothermal fields in the area by injecting hundreds of tons of water and carbon dioxide gas into the rocks

“We take CO2 and wastewater from the same geothermal power plant (in Hellisheiði) and inject them together. The CO2 dissolves and, like in a bottle of sparkling water, it stays dissolved as long as it's sealed. It then reacts with calcium and magnesium silicates in rocks to form carbonates,” geologist Juerg Matter of the University of Southampton told New Scientist.

Read more: Nine fascinating facts about geothermal energy and Reykjavík

The geothermal areas in the Hengill region are among the most powerful high-temperature fields in Iceland.

RE’s power plant system is by far the largest Icelandic municipal geothermal heating service, supplying 56% of the population of the country with hot water.

Read more: Geothermal power generates higher living standards, lower heating costs and less pollution

The last eruption in Hengill was approximately 2,000 years ago.

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