Closer Look: It’s Volcano Time

While waiting for Iceland to (possibly) erupt, we take a closer look at Icelandic and global volcanism.

Beth Johnson

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Several spread out groups of people in winter clothes stand and sit, watching the eruption of a cinder cone volcano in Iceland in 2021.
Credit: Berserkur via Wikimedia Commons

One of the daily activities that is helping me stay sane is volcano watching. I love volcanoes. I especially enjoy when they erupt in places that have webcams but don’t affect the lives of people. Unfortunately, those are both rare, unless, it seems, you are in Iceland.

Over the past decade, Iceland has given us hours of entertainment watching lava flow out from rifts and cones. People gather nearby to watch, set up webcams for science, and even fly drones to catch amazing imagery that they then share with the world at large. And as long as no one gets hurt, that’s fine.

But volcanoes aren’t always polite. In fact, they usually are not polite. They erupt where people live, partially because we keep building near them for the rich soil. They erupt in backyards. They destroy towns. And when your home is on a volcanic island created by both a hot spot and the Mid-Atlantic Ridge, there’s always a risk that magma will find its way up through the rocks under you.

Terrain map view of Iceland around Grindavik, showing a recent spat of earthquakes due to magma emplacement.
Credit: Icelandic Met Office

Such seems to be the case with the town of Grindavik in the southwest of Iceland. For weeks now, scientists have been collecting data on earthquake swarms and ground deformation around and under and within the town. Thousands of earthquakes have shaken the region since October 25, marking a magmatic intrusion about 3 to 3.5 kilometers below the surface. Measured subsidence on the west side of Grindavik has been on the order of 1.5 meters, while the uplift caused by the dike’s emplacement to the northeast of the town has continued at a steady rate. Additionally, instruments in the area are measuring elevated areas of sulfur dioxide, a potential sign of magma getting ready to breach the surface.

On November 10, the entire town was evacuated, displacing nearly 4,000 people and their animals, including pets and livestock. Drone footage has shown a large crack forming in the city, and steam from the broken water pipes below ground has been escaping. From our own analysis of the footage…

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Beth Johnson

Planetary scientist, podcast host. Communication specialist for SETI Institute and Planetary Science Institute. Buy me a coffee: https://ko-fi.com/planetarypan