The largest earthquake, magnitude 5.6 on the Richter scale, occurred on the morning of February 24. It was the loudest in a swarm involving the residents of the nearby capital Reykjavík and the surrounding municipalities, where two-thirds of the Icelandic population lives. Two larger earthquakes – over magnitude 5.0 – also hit February 27 and March 1.
The earthquakes have caused little damage so far, although the Icelandic Road and Coastal Administration has reported small cracks in roads in the area and rock faces on steep slopes near the swarm’s epicenter.
In the fishing village of Grindavík, the locals have been sitting in the front row because of the vibrations. “I’ve never seen anything like it,” said Páll Valur Björnsson, who teaches at the local Fisheries College and is a Deputy Member of Parliament.
“We’re used to it; it started a year ago. But it’s much more now – very disturbing. I’m not scared, but this is uncomfortable. I woke up twice last night because of [tremors]There was a really big one when I went to sleep, and I woke up with one. It’s difficult, but you have to learn to live with it, ”he said.
Only this time there doesn’t seem to be an end to the rumble underground.
Þorvaldur Þórðarson, a professor of volcanology at the University of Iceland, said concerns about the recent activity are understandable. “Of course it worries people. For this region this is actually quite unusual, not because of the type of earthquakes or their intensity, but because of their duration. It has been going on for over a week now.”
“We are currently struggling with the ‘why’. Why is this happening? [Earth’s] crust there. It’s certainly got closer to the surface, but we’re trying to find out if it’s moving even closer to it, “he said. With multiple volcanoes in the area, local officials have warned that an eruption could be imminent.”
Elísabet Pálmadóttir, a natural hazard specialist at the Icelandic Meteorological Bureau, told CNN that authorities are deploying surveillance equipment in the area, from GPS and earthquake monitors to web cameras and gas detectors.
She, too, cannot remember ever experiencing so many earthquakes in such a long time. She warns that a more powerful event could be cause for concern, and estimates that the area could experience a magnitude 6 earthquake or higher.
“In this particular area, where we’ve seen activity for the past week, we could experience a magnitude 6.0 earthquake. But we could have a 6.5 magnitude east of the area, east of the Kleifarvatn- more, ”she says.
According to the latest models from the University of Iceland’s Volcanology and Natural Hazard Group, which published maps of potential flows on Wednesday, no city appears to be at risk from lava flows in the event of a volcanic eruption.
“Based on the current model, no major city is at risk,” volcanologist Ármann Höskuldsson told CNN, adding that Keflavík International Airport – one of the most direct connections between Iceland and the rest of the world – would also be spared.
However, the main road connecting the airport to the capital Reykjavík could be affected, as well as some power lines, he added.
Pálmadóttir notes that such models do not take into account potentially dangerous gases that could be emitted from a volcanic eruption.
Þórðarson adds that “the magma composition is very different here, the intensity of explosive activity would be considerably less.”
On Wednesday afternoon, a quake near the Keilir volcano, just 30 kilometers south of the capital, banned traffic in the area. On its webpage, the Icelandic MET agency says similar activities have preceded eruptions before.
Víðir Reynisson, Chief Superintendent of Iceland’s Civil Protection and Disaster Response Department, told a press conference on Wednesday that an eruption is “more likely than not” within the next few hours. It would be the first in the area since the 12th century.
For now, residents are waiting for signs of an eruption, some with excitement, others with fear. Víkurfréttir, a local news service, has installed a video camera pointing to Keilir, which starts live streaming when an eruption begins.
In the past 24 hours, the major earthquakes of the past few days had largely disappeared, but the current pause may not be long. “It is certainly not over,” says Pálmadóttir.