Q

What’s the situation on the Reykjanes peninsula? Is there going to be another eruption?

A

It has been a time of upheaval for the Southwest Iceland 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.

As of late November, the most likely location for an eruption is considered to be between Sýlingarfell and Hagafell mountains, northeast of Grindavík and east of Svartsengi Power Station and the Blue Lagoon. While the evacuation order remains in effect, Grindavík residents are permitted to enter the town to retrieve belongings and maintain their homes and properties. Some businesses in the town have also restarted operations.

As always, volcanic activity is difficult to predict. As the last eruptions on the Reykjanes peninsula have shown, Iceland has some of the best-monitored volcanoes in the world, but despite this, when, where, and if an eruption will occur can be difficult to say with precision, even for experts. With that warning out of the way, here’s what we know so far about the latest phase of seismic activity on the Reykjanes peninsula.

Earthquakes and uplift on Reykjanes

An earthquake swarm began on the Reykjanes peninsula on the night of October 24, 2023 just north of the town of Grindavík. On October 27, the land in the area began to rise, indicating a magma intrusion in the earth below. The intrusion was later confirmed by experts, some 4-5 kilometres [2.5-3.1 miles] below the surface of the peninsula, not far from where three eruptions have occurred over the last three years.

The magma intrusion has since grown and lengthened to stretch below the town of Grindavík and out to sea. In late November, some experts suggested that most of the magma in the intrusion had solidified, though fresh magma was still believed to be streaming in. So far, no volcanic unrest has been detected. This is the fifth time that deformation has been measured at this location since 2020. None of the previous instances resulted in an eruption.

Threat posed to Svartsengi power plant

Current data and measurements indicate that another eruption on the Reykjanes peninsula is still a possibility. Given the possible location of an eruption, there is a real danger posed to operations at Svartsengi, which is the main supplier of electricity and water to the Reykjanes peninsula. Iceland’s Parliament passed a bill on November 13 to enable the building of lava barriers around the power plant and the Blue Lagoon and construction has begun and is ahead of schedule.

Town of Grindavík

In the path of an eruption for the fourth time now, Grindavík was evacuated on the evening of November 10 according to existing evacuation plans. Residents have since been permitted to enter the town temporarily to retrieve belongings, valuables, and pets that may have been left behind. The town has experienced significant damage due to the ongoing seismic activity, including cracks in roads and buildings, damage to water and electrical infrastructure, and crevasses that have opened up throughout the town. Experts have stated that an eruption would be preceded by shallow earthquakes and volcanic unrest, which would give at least 30 minutes warning before magma broke through above ground.

Tourism affected

The Blue Lagoon was closed on November 9, initially only until November 16. The company came under some criticism for not closing operations earlier, especially after tour operator and transit company Reykjavík Excursions ceased trips to the lagoon on November 7, citing concerns for staff and customer safety. On November 14, the closure was extended to November 30 and was later extended until December 7.