James Stewart

Terrifying, absolutely, but also a geological warning.

Something was going on just a few kilometres below the surface.

Seismic swarms can be caused by magma forcing its way up through cracks in Earth's crust, in what's known as an intrusion.

Rock fractures, magma floods in, pressure builds, and it's often only a matter of time until it reaches the surface.

In March 2021, the ground finally gave way, and a fissure ripped open in Fagradosh Vyakh.

I said I'd come back to this place, and it went on for nearly six months before suddenly stopping.

But that was not a return to dormancy.

That was just the start.

Further eruptions followed in 2022, and again in 2023.

Then the activity began to migrate, shifting a few kilometres southwest to Svart Sengi, along the Sundsnuknigal crater row.

It was closing in fast.

On the 10th of November 2023, the decision was taken to evacuate the town of Grintovik, home to 3,700 people.

The telltale seismic swarm showed that a major magma intrusion was propagating beneath the town.

Days after the evacuation, fissures opened, destroying homes and damaging infrastructure.

It was described as Iceland's most severe natural disaster in 51 years, and Grindavik remains largely uninhabited today.

For geologists, this was the final confirmation needed that a long, quiet volcanic system had awoken.

The starting pistol for a centuries-long eruptive cycle.

But how do they know this is only the beginning?

By bringing Viking sagas into the satellite age.

This, my friends, has happened before.