Magma Could Threaten Grindavík Again (and Again)

grindavík evacuation

Magma may start flowing into the dike underneath the town of Grindavík again days or months from now. The Icelandic town remains evacuated and experts say it is not clear when it will be safe for its residents to return to their homes. While an eruption near the town, located on the Reykjanes peninsula, is now considered less likely in the short term, a new phase of seismic activity may be beginning.

In late October, an earthquake swarm and uplift began on the Reykjanes peninsula near the town of Grindavík indicating magma collecting underground. The magma intrusion grew and filled a dike stretching beneath the town, leading authorities to issue an evacuation order on November 10 due to the risk of eruption.

A new chapter of activity

Magma inflow to the dike has likely stopped, according to a notice from the Met Office, and the chances of an eruption happening along the dike at this time have decreased. However, magma continues to accumulate just north of Grindavík, beneath Svartsengi, where a geothermal power plant and the Blue Lagoon are located. “The ongoing activity at Svartsengi, which began in October, is not yet over and a new chapter may have begun with an increased chance of a new magma propagation and, subsequently, increased likelihood of an eruption,” the Met Office notice states.

“[T]he dike beneath Grindavík was fed by magma accumulating beneath Svartsengi. It is likely that this sequence of events will repeat,” the notice continues. A new magma propagation would provide a warning in the form of earthquakes and ground deformation, which would be detected by equipment “several hours before the magma propagation is likely to pose a threat to Svartsengi or Grindavík.”

Timeline impossible to estimate

According to the Met Office, this pattern of magma accumulating beneath Svartsengi and flowing into the dike that stretches below Grindavík is likely to happen again, even repeatedly. However, it is impossible to estimate whether that will be “in the next few days or possibly after several months.”

Kristín Jónsdóttir, Head of the Volcanos, Earthquakes, and Deformation Department at the Icelandic Met Office, told RÚV it was not clear when it would be safe for Grindavík residents to return to their homes.

Chances of Eruption in Grindavík Diminishing

Svartsengi Grindavík

The most likely location of an eruption on Reykjanes is now considered to be north of Grindavík and east of Svartsengi Power Station and the Blue Lagoon, according to experts. The likelihood of an eruption has, however, diminished overall. The construction of lava barriers to protect the power station is ahead of schedule and while an evacuation order remains in effect, regulations on entering Grindavík for residents and business operators have been relaxed.

It has been a time of upheaval for the town of Grindavík (pop. 3,600), which was evacuated on November 10 amid powerful seismic activity. Earthquakes and the formation of a magma dike under the town have opened crevasses and damaged roads, homes, and infrastructure in and around Grindavík. An eruption is still considered a possibility, though the likelihood of one has diminished.

Grindavík eruption less likely

One of the reasons Grindavík was evacuated was that experts could not rule out an eruption in the town itself. Now, the most likely location of an eruption is considered to be between Sýlingarfell and Hagafell mountains, northeast of Grindavík and east of Svartsengi Power Station and the Blue Lagoon.

Data indicates that magma is continuing to stream into the magma dike that stretches below Grindavík and northeast from the town. However, some experts have suggested that the magma in the dike is partly solidified, though it would take months for it to solidify fully. While an eruption is still possible, it is considered to be less likely than previously believed. The likelihood of an eruption within the town limits of Grindavík is also considered less and less likely to occur.

Lava barriers ahead of schedule

The construction of lava barriers, which began around two weeks ago, is ahead of schedule, the Director of the Civil Protection and Emergency Management Department told RÚV. The barriers are to surround Svartsengi Power Plant and the neighbouring Blue Lagoon, and are expected to take 30-40 days to complete.

While an evacuation order remains in effect for Grindavík, authorities have relaxed restrictions for the town’s residents and businesses, who are permitted to enter the town in order to take care of their property and retrieve belongings. Some businesses have also begun operating once more during daytime hours. While some of the town’s water and power infrastructure sustained damage in the recent earthquakes, water and power are functional in much of the town and repairs are being conducted.

Iceland’s Parliament passed a bill yesterday to provide financial support to businesses in Grindavík whose operations are impacted by the evacuation. The support is intended to help businesses continue to pay out employee salaries over the coming months.