Why an expected volcano eruption in Iceland won't be like the chaos seen in 2010

Earthquakes indicate eruption could happen within days or even hours, experts warn

Lava spurts after the eruption of a volcano in the Reykjanes Peninsula, Iceland in July. A town near Reykjavik has been evacuated over fears of a similar explosion. Reuters

A volcanic eruption near Iceland's capital Reykjavik is unlikely to result in the major disruption to air travel that occurred in 2010, according to experts.

A town that is home to 4,000 people could be heavily damaged by a volcano expected to erupt imminently after recording more than 1,000 earthquakes in recent days.

Grindavik on the south-western coast was evacuated in the early hours of Saturday after magma shifting under the Earth’s crust caused hundreds of earthquakes in what is believed to be a precursor to an eruption.

“We are really concerned about all the houses and the infrastructure in the area,” Vidir Reynisson, head of Iceland’s Civil Protection and Emergency Management, said on Saturday.

The town – about 40km south-west of Reykjavik – is near the Svartsengi geothermal plant, the main supplier of electricity and water to 30,000 residents.

David Pyle, volcanologist and Professor of Earth Sciences at the University of Oxford, said the movement indicated a large intrusion of magma has formed a dyke, or ‘magma tunnel’ which stretches for about 15km and lies at about three to five kilometres underground.

“This dyke extends directly underneath the town of Grindavik. Over the weekend, the number of earthquakes fell, but the ground deformation continued,” he said.

“The scientists at the Icelandic Met Office consider it likely that magma is rising closer to the surface, and that there is a substantial chance of an eruption.”

Scientists say if the volcano does erupt it is likely to follow the pattern seen from 2021 to 2023 at Fagradalsfjall volcano, with lava flows and ‘fire fountaining’ if the eruption begins on land.

It is not likely to resemble the 2010 Eyjafjallajökull eruption, which cost airlines an estimated $3 billion due to the cancellation of more than 100,000 flights due to ash clouds.

“The Eyjafjallajokull eruption of 2010 was quite different as it was associated with a shield volcano topped by a glacier. It was the interaction of the magma with ice and meltwater that made that eruption so explosive and dangerous for aviation. This is not the case for Fagradalsfjall,” said Dr Michele Paulatto of Imperial College London.

She said toxic fumes are “a real concern”, and could result in breathing problems.

“It’s not something we need to worry about in the UK, but the local population and tourists can be affected depending on the prevailing wind direction,” said Dr Paulatto.

“So, in summary, at Fagradalsfjall any eruption is likely to be effusive unless it happens under the sea or very near the coast. It could be large, based on the size of the dyke and the magnitude of the ground deformation, but is unlikely to be similar to the Eyjafjallajokull eruption of 2011.

“Evacuations could last a long time but are likely to affect only a relatively small area.”