Comment on this storyCommentAdd to your saved storiesSave
Icelandic officials have evacuated the town of Grindavik, warning that a volcanic eruption was imminent. Cracks have appeared in the earth there, snaking under buildings, splitting roads and sending steam into the air. Even though magma has not yet bubbled to the surface, experts believe it will soon.
The volcanic activity is taking place on the Reykjanes Peninsula, about 25 miles southwest of Reykjavik, the capital of Iceland. On the peninsula, the North American and Eurasian tectonic plates are pulling apart, causing magma to periodically bubble to the surface in a long history of eruptions.
Volcanism was dormant for almost 800 years until it suddenly awakened in 2020. Then the Fagradalsfjall volcano erupted on March 19, 2021. Volcanic coughing and sputtering has occurred since then, but a major eruption may be inevitable in the coming days.
In fact, the Icelandic Meteorological Office warned on Monday of a “significant probability of a volcanic eruption in the coming days.” It is believed that beneath Grindavik there is a “dyke intrusion,” or a magma fissure that squeezes between crustal rocks. On Saturday, the Met Office said the magma was probably less than 800 meters, or 2,624 feet, from the surface.
Initially, a spate of earthquakes – including two over the past week with a magnitude of over 5.0 and thirteen with a magnitude of 4.5 or greater – were centered about two miles northeast of Grindavik, a town of 3,300 on the Reykjanes River. Peninsula. It is believed that magma rises there.
Over the past 72 hours, the quakes moved slowly southwest, alerting scientists to the possible movement of magma. The ground has also risen by around one meter in the west of Grindavik. The total magma intrusion is estimated to be approximately 10 miles long and continues southwest into the sea. Around 100 earthquakes are still shaking the region every hour.
According to the Met Office, police on Sunday allowed displaced residents of Thorkotlustadahverfi, a suburb of Grindavik, to return home “only to collect essential items, pets and livestock”. The roads to and from Grindavik remain closed. Iceland’s popular Blue Lagoon thermal spring will also be closed until at least 7 a.m. on Thursday, when a decision will be made about whether to reopen or remain closed.
Earthquakes and volcanoes are no stranger to Iceland. In 2010, the Eyjafjallajokull eruption on the south coast of Iceland ejected 330 million cubic meters of material and spewed ash 30,000 feet high. The ash cloud forced the closure of most of European airspace for almost a week.
In the southwest, an entirely new island – Surtsey – emerged from nothing after an undersea volcanic eruption reached the ocean’s surface on November 14, 1963. The eruption lasted until June 5, 1967, when the island was 1.68 miles wide and 509 feet tall. Since then, wave action has eroded much of the island.
In the case of the Reykjanes Peninsula, the parent volcano Fagradalsfjall had remained quiet for 6,300 years until December 2019. Then a swarm of earthquakes, including two magnitude 5.6 tremors, shook the peninsula. On February 4, 2021, an even larger earthquake of magnitude 5.7 occurred, causing damage. On March 19 of that year, a 2,000-foot-long fissure opened and lava emerged.
The new structure, called Geldingadalsgos, is considered a possible new shield volcano – a wide volcano with gently sloping sides. Several more cracks opened in April 2021, but only one remained active until May of this year.
Another eruption from a separate fissure of Fagradalsfjall occurred on August 3, 2022.
Then, in early July this year, a new eruption began near Litli-Hrutur, also part of the Fagradalsfjall volcano. It was about ten times larger than the first two eruptions. By August 5th the number decreased.