Experts on high alert for Iceland eruption as town on magma river sinks by a metre 

Scientists say seismic activity in Iceland that caused a town of 4,000 people to be evacuated on the weekend may result in a prolonged volcanic eruption. 

The coastal town of Grindavik, 40km southwest of the capital Reykjavik, was entirely evacuated after the nation’s police commissioner declared a Civil Protection Service Level of Emergency in response to increased seismic activity last week. 

Iceland is located on top of two major tectonic plates pulling apart from one another. Fears are growing that an eruption is imminent with more than a thousand earthquakes rocking the North Atlantic island this week.  

Though a national government statement noted “seismic activity is part of Icelandic life and this potential eruption is likely to impact a limited local area of the country”, its Met Office considers there to be a high likelihood of an eruption. Volcanic activity in the region has been persistent for at least two years, with three previous eruptions nearby.  

If a major eruption does occur, it’s predicted to take place at a magma dike spanning around 15km across the Reykjanes peninsula, with Grindavik sitting atop it. Already a large area surrounding the township has sunk between 0.5-1m.  

A satellite image heatmap of shifting elevation around grindavik, iceland
A satellite image heatmap of shifting elevation around Grindavik, Iceland. Blue and Purple areas indicate vertical sinking of around 1m. Credit: Met Office, Iceland

“The imminent eruption in Iceland is unlikely to cause the chaos that we saw with the Eyjafjallajökull eruption,” says Dr Sabin Zahirovic, a geologist at the University of Sydney.  

“However, the 15-km-long magma chamber of this new eruptive zone will likely feed major lava flows that will threaten Grindavik and nearby infrastructure, including a major geothermal power plant. Any eruption is likely to be ongoing for months, and possibly years into the future.” 

Should the eruption take place beneath the sea, or if lava flows into the ocean, the interaction between the molten rock and water will result in small explosions.

Hundreds of earthquakes have been measured each day for the past week, a further 800 occurred on Wednesday local time, as large cracks began to emerge through the area. 

This photo taken on november 13, 2023 shows a crack cutting across the main road in grindavik, southwestern iceland following earthquakes. The southwestern town of grindavik -- home to around 4,000 people -- was evacuated in the early hours of november 11 after magma shifting under the earth's crust caused hundreds of earthquakes in what experts warned could be a precursor to a volcanic eruption. The seismic activity damaged roads and buildings in the town situated 40 kilometres (25 miles) southwest of the capital reykjavik, an afp journalist saw.
A crack cuts across the main road in Grindavik, southwestern Iceland following earthquakes. Credit: Kjartan Torbjoernsson/AFP via Getty Images

“It’s a hairy situation, but one thing in Iceland’s favour is that they have organised themselves really well for early warning systems and information flow,” says Dr Andrew Tupper, a specialist meteorologist at Natural Hazards Consulting in Australia. “The Icelandic Met Office, which is responsible for geohazard and severe weather warnings, is a world leader in that respect.” 

Icelanders live on a 500km wide island built on the boundary of the North American and Eurasian plates.  

Officials are likely to use earthquake measurements, satellite monitoring of land deformation and volcanic gas chemistry to guide management of the situation over the coming days. 

While many specialists anticipate an eruption, it’s unlikely to cause major international disruptions on the scale of Eyjafjallajökull, a stratovolcano located about 140km east of Grindavik, which had several eruptions in 2010.  

Eyjafjallajökull’s most explosive phase resulted in a substantial ash plume spreading across most of Europe, Russia and parts of North America, which halted international air travel at a cost of $2.5 billion. 

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