On The Road – Christopher Mathews – Iceland: Holiday Fires

Christopher Mathews

A volcanic eruption is underway in southwestern Iceland.  The fourth in three years, this one is the most powerful so far, and the most dangerous.

In 2020, geologists noted movements in the Earth’s crust near the Svartsengi power station, one of Iceland’s many geothermal power plants.  Located about 25 miles from the capital city Reykjavík (and a much shorter distance from Iceland’s main airport, at Keflavík), Svartsengi provides electrical power to the Icelandic grid, and hot water to heat thousands of Icelandic homes.  The famous Blue Lagoon spa is located right next door.

The most important feature of the 2020 event was uplift around the power station, indicating an inflow of magma which began pooling about three miles below the surface.  The 2020 event tapered off by mid-year, with GPS measurements showing a bulge in the landscape spread across several square miles.  Another inflation event took place in 2022.

In the meantime, a series of eruptions were taking place at Fagradalsfjall, a long-dormant volcano several miles to the east.  Eruptions in 2021, 2022, and the summer of 2023 focused most attention away from Svartsengi.  But the bulge emplaced over the prior years remained, indicating the continuing presence of a large underground reservoir of magma called a sill.  As long as it remained safely below ground, though, that magma was not a cause for immediate concern.

On October 25 of this year, a strong pulse of fresh magma into the sill caused the earth to rise again.  This time, the uplift was rapid and dramatic, triggering dozens of sharp earthquakes.  Operators at the power station rigged it to be run remotely.  Tourist visits to the Blue Lagoon (and the hotel on the premises) dropped off sharply, and bythe first week in November, the spa was closed.  Everyone waited.

On November 10, 2023, something in the underground reservoir broke.  Earthquakes that had been counted in the hundreds per day multiplied suddenly to hundreds per hour.  By evening, it was clear the magma was on the move – but where?  Shortly before midnight, the authorities declared a state of emergency for the region.  The nearby harbor town of Grindavík, home to about 3500 Icelanders – about one percent of the entire national population – was given four hours to evacuate.  They did it with 90 minutes to spare.

And then we waited some more to see what would happen.

When the sun rose on the 11th, the earthquakes began to die down.  Grindavík was now a badly battered town, with broken water and power mains, torn roads, shattered buildings.  There were fissures up to 75 feet deep.  The western half of the town had dropped in the night and was now about four feet lower than the east.  But there was no eruption, and after a few tense days of waiting, the residents were allowed to go in in small numbers, accompanied by police and search and rescue teams.  Pets who had been outdoors when the nighttime evacuation got underway, livestock from local farms, and other precious items were on the retrieval lists.  The coast guard stood offshore to render aid if needed.

Geologists quickly determined that the evening of November 10, the underground magma lake had drained into a subterranean fault zone east of the power plant.  The sill deflated, and the drained magma formed a dike running directly under Grindavík.  Now squeezed into spaces just a few hundred feet below the surface, this new channel of magma extended both north and south beyond the town.  As the days went by, and the magma stayed underground, residents began the hard work of repairing their roads and other infrastructure and assessing the cost of the seismic swarm.  The evacuation orders stood.  But there was hope that perhaps the Earth would go quiet, and the town could return to life.

And then sill began to reload, and the ground began to rise again.

When December began, the Earth’s crust at Svartsengi was back at its early 2023 levels and ballooning rapidly.  More than three years’ worth of uplift recurred in less than thirty days.  On December 17, the ground was higher than it had been when the sill broke and earthquakes ripped the town.  But remarkably, the Earth remained mostly still.

The evening of the 18th, however, the ground began to move again.  At 10:17 local time, it split open along a miles-long fissure north of Grindavík and lava began fountaining hundreds of feet into the night sky.

As I write this, we are six hours into the eruption.  Dozens of square miles have been covered with lava – but not, so far, the town or the power plant.  Volcanic gases have spread much further: I can smell the acrid odor of sulfur dioxide at my home, fifty miles from the eruption.  There‘s no telling how long the event will last, or exactly where the lava will go.  Volcanoes are like cats: they do what they want, when they want.  And they don‘t care if they break your stuff.

Eventually, this eruption will end.  Icelanders are a resilient lot, and will make the most of the new landscape.  For now we wait and watch some more.

This is an amazing place to live, and an awesome time to live here.