A volcano spews lava and smoke as it erupts near Grindavik, on Reykjanes Peninsula, Iceland.
| Photo Credit: Reuters

A volcano in southwestern Iceland erupted on Wednesday for the fifth time since December, spewing red lava that once again threatened the coastal town of Grindavik and led to the evacuation of the popular Blue Lagoon geothermal spa.

The eruption began in the early afternoon following a series of earthquakes north of the town of 3,800 people that was largely evacuated in December when the volcano came to life after centuries of dormancy and put on an impressive show of nature’s power.

Although activity began to calm down by early evening, initial estimates found the eruption was the most vigorous in the area so far, as lava shot 50 meters (165 feet) into the sky from a fissure that grew to 3.5 kilometers (2.1 miles) in length, the Icelandic Meteorological Office said.

Barriers built to protect Grindavik deflected the flowing lava that cut off two of the three roads leading to town and was close to reaching the third.

“It’s a much larger volume that’s on the move right now headed for town,” Grindavik Mayor Fannar Jónasson told national broadcaster RUV. “The lava has already conquered (a lot).”

Workers and anyone still in town were ordered to leave earlier in the day, police said.

At one point, a dark plume of ash boiled up over the crater from an explosive interaction of magma hitting groundwater, scientists said.

The cloud did not rise high enough to initially pose any threat to aviation, but scientists were closely monitoring the situation, Jóhanna Malen Skúladóttir, of the Met Office, told RUV.

Grindavik, which is about 50 kilometers (30 miles) southwest of Iceland’s capital, Reykjavik, has been threatened since a swarm of earthquakes in November forced an evacuation in advance of the initial Dec. 18 eruption. A subsequent eruption overwhelmed some defensive walls and consumed several buildings.

The area is part of the Svartsengi volcanic system that was dormant for nearly 800 years before reawakening.

The volcano erupted again in February and March. The Feb. 8 eruption engulfed a pipeline, cutting off heat and hot water to thousands of people.

Iceland, which sits above a volcanic hot spot in the North Atlantic, sees regular eruptions and is experienced at dealing with them. The most disruptive in recent times was the 2010 eruption of the Eyjafjallajokull volcano, which spewed huge clouds of ash into the atmosphere and led to widespread airspace closures over Europe.

Lava spurts and flows after the eruption of a volcano in the Reykjanes Peninsula, Iceland, July 12, 2023, as seen in this handout picture taken from a Coast Guard helicopter.
| Photo Credit: Civil Protection of Iceland/Reuters

A seismic swarm has hit the Reykjanes peninsula in southwest Iceland with more than 5,500 small earthquakes in the last three days, raising the prospect of a volcanic eruption, the country’s meteorological office (IMO) said on Friday.

Located between the Eurasian and the North American tectonic plates, among the largest on the planet, Iceland is a seismic and volcanic hot spot as the two plates move in opposite directions.

While quakes are a daily occurrence in Iceland, the latest swarm was more extensive than usual.

“These earthquakes are a warning sign, a part of a longer-term story that we know we’re entering a build-up phase to the next (volcanic) eruption,” IMO Service and Research division head Matthew Roberts told Reuters.

The quakes originated at a depth of up to 5 km and were caused by a long-term accumulation of magma that has been building pressure and is now slowly drifting towards the surface of the earth, he added.

Earlier this year a volcano erupted in an uninhabited part of the Reykjanes peninsula after intense earthquake activity, the third such event in the region southwest of the capital Reykjavik since 2021.

A fourth eruption could now be developing, the IMO said, although predicting the timing of volcanic outbreaks is difficult.

“From my perspective as a scientist and someone who’s been following this activity very closely, I would say that an eruption within the next 12 months is likely,” Roberts said.

The strongest of the earthquakes had been measured at a magnitude of 4.5, and around 15 tremors were at 3.0 or stronger, the IMO said.

Earthquakes with a magnitude above 2.5 can often be felt by humans, according to the Michigan Technological University.

Grindavík, a fishing town on the peninsula with around 2,000 inhabitants, is the town closest to the seismic activity.