“At the moment we’re feeling it constantly. It’s like you’re walking over a fragile suspension bridge,” said Rannveig Gudmundsdottir, a lifelong resident in the town of Grindavik.
Grindavik is located in the southern part of the Reykjanes Peninsula, a volcanic and seismic hot spot. Since February 24, 2021, there have been over 40,000 earthquakes, exceeding the total number of earthquakes registered there last year, according to Reuters.
Iceland is the world’s 18th-largest island, and Europe’s second-largest island after Great Britain. Over two-thirds of the country’s population of 364,000 people live in the southwest of the country. Iceland’s capital, Reykjavík, is also located in the southwest of the country.
Geographically, Iceland lies between the Eurasian and the North American tectonic plates and experiences frequent earthquakes as the two plates move in opposite directions from each other at a pace of 3.0 centimeters (0.79 inches) a year.
The source of all the recent seismic activity is a large body of molten rock, or magma, moving roughly 1.0 kilometers (0.6 miles) beneath the peninsula, as it tries to push its way to the surface, reports The Guardian.
“We’ve never seen so much seismic activity,” says Sara Barsotti, volcanic hazards coordinator at the Icelandic Meteorological Office (IMO). Some of the quakes have registered as high as a magnitude 5.7.
“Everyone here is so tired,” says Gudmundsdottir, a schoolteacher. “When I go to bed at night, all I think about is: am I going to get any sleep tonight?”
Many people in Grindavik have visited relatives, spent time in summer homes, or gone to Reykjavik and rented a hotel room, just to get a good night’s sleep. Authorities have warned of an imminent eruption on the peninsula since early March.
Unlike the eruption of the Eyjafjallajökull volcano in 2010, which halted over 900,000 flights and forced hundreds of Icelanders from their homes, the eruption on the peninsula won’t be quite as dramatic. Experts are expecting lava to erupt from fissures in the ground, possibly resulting in spectacular lava fountains, which could extend 20 to 100 meters (95 to 328 feet) in the air.
An end to the earthquake swarm
According to Halldór Geirsson, associate professor of geophysics at the University of Iceland, an eruption would release the buildup of pressure caused by the flowing magma. His colleague Professor Emeritus Páll Einarsson agrees, according to the Iceland Monitor.
But even they are not absolutely sure. While they believe an eruption will end the swarms of earthquakes, it is possible that the earthquakes could subside without an eruption taking place.
There appear to be four magma intrusions or dykes in the region at the present time. The magma dyke causing the present quakes, though, is by far the largest, Halldór states. It extends from Keilir mountain to Fagradalsfjall mountain.
The other magma three intrusions appear to be near Svartsengi (north of Grindavík), in the volcanic system on Reykjanes point (the westernmost part of the peninsula), and by Krýsuvík (near Kleifarvatn lake). They are depending on GPS data to follow the intrusions.
“We try to read this GPS data to see whether the magma dyke is moving or expanding,” Halldór states. “We clearly see that it continues to expand; the movements are in line with the seismic activity; this is moving south-southwest. The magma dyke is expanding in that direction,” he concludes.