Icelandic volcano previously dormant for 800 years erupting again

A once long-dormant volcano in Iceland is erupting again and impacting activity in a populated region nearby.

The volcano, on the Reykjanes peninsula in southwestern Iceland, began erupting at Sundhnukar on Wednesday night and peaked at about 2 a.m. local time Thursday, according to the Icelandic Meteorological Office. It has prompted evacuations at the Blue Lagoon, an iconic tourist destination, and the nearby town of Grindavik.

West Iceland's volcano is a rift activity volcano, which involves the earth being pulled apart in two different directions through the Mid-Atlantic Ridge, rather than a cone erupting magma through a central pipe, Thomas Algeo, a professor of earth sciences at the University of Cincinnati, told ABC News. The style of eruption is "much less dangerous, because most of the activity involves slow moving basaltic lava flows," he added.

"It's a style of volcanic activity that is effusive, slow flowing, not violently eruptive, like would be the case with a subduction zone volcanic system" Algeo said.

The fissure that was created on Wednesday night stretched about 1.8 miles long, according to the country's meteorological office. This is the volcano's seventh eruption this year, according to Iceland's Department of Civil Protection and Emergency Management.

These types of eruptions are "spectacular" sights, because once a fissure opens up, a large supply of magma oozes out, Tobias Fischer, director of the Volatiles Laboratory at the University of New Mexico, told ABC News.

The eruption activity is "typical" for these types of systems, said Shawn Willsey, a geology professor College of Southern Idaho who has been conducting livestream tours using drones above the lava flows on YouTube. Once the lava erupts, the pressure is relieved and magma starts to fill into the shallow storage zone below -- repressurizing the system and setting the stage for the next eruption, Willsey said.

"It's known that this region goes through these episodes where there are a lot of these eruptions," said Fischer, who has flown drones into eruption gas clouds to collect samples and analyze the composition of the carbon for his research.

By Thursday afternoon, the lava had reached the parking lot of the Blue Lagoon and consumed a service building, The Associated Press reported. There is no danger to the area, and the flights out of the Keflavik International Airport have not been affected, according to the civil protection agency.

Gas emitted from the eruption is expected to move south and out to sea, according to emergency officials.

Video taken from Grindavik show rivers of fast-moving lava flowing from the rift zones, where the lava can be seen spewing from the ground.

The ongoing eruption is "significantly smaller" than the eruption that took place in August, according to the meteorological agency.

Iceland is known as a "hot spot" for volcanic activity, Algeo said.

There are 32 active volcano systems in the region spread across three rift zones spread to the north, south and west -- all part of the Mid-Atlantic Ridge, a mountain range that mostly runs down the middle of the Atlantic Ocean.

But in Iceland, the mountain range comes above the ocean certain due to "an excessively high production of magma in that area," Algeo said.

Iceland's western rift zone, also known as the Reykjanes-Langjökull rift zone, was active prior to the 13th century. These types of eruptions tend to have every 1,000 or so years, Fischer said,

"The big question is, is this going to continue on for centuries?" Willsey said.

In 2021, the volcano in western Iceland became active again. There have been 10 eruptions since there, seven of which have occurred in 2024, according to Icelandic officials said.

During the last 800 years, the majority of volcanic activity were in the north and east volcanic zones -- both lightly populated regions, Algeo said. But western Iceland, which includes the capital of Reykjavik, is highly populated.

"They were in a nice little valley up in the mountains, and so that lava was pretty well contained," Willsey said, adding that lava in those regions are "tourist-friendly" eruptions that can be enjoyed with little threat.

The recent eruptions in western Iceland have damaged infrastructure and property and forced residents to relocate, according to AP.

Previous eruptions throughout history have caused destruction in Iceland, Algeo said.

A large eruption that took place in 1783, known as the Laki eruption, is one of the worst in recorded history. It spewed so much toxic volcanic gasses across the landscape that it killed off most of the local farm animals and reduced the harvest, leading to starvation for about 25% of the population, Algeo said.

Eruptions on the Reykjanes peninsula in December 2023 triggered toxic gas warnings, causing emergency managers to fear that the pollution would spread to the capital.

A disruptive eruption at the Eyjafjallajokull volcano in 2010 disrupted trans-Atlantic air travel for months due to ash being spewed into the air.