Ask a Geologist: With Its Several Hotspots, Could Reykjavík Erupt?

We asked geologist Ed Marshall, a postdoc in Mantle Geochemistry and Igneous Petrology at the University of Iceland: do Reykjavík’s several geothermal hot spots indicate that the city could turn into the scene of a Hollywood disaster movie. To put it simply: could Reykjavík erupt?

In short, no. A volcanic incident in Reykjavík or its immediate vicinity is basically geologically impossible. But that doesn’t mean that volcanic activity couldn’t have an impact.

Iceland sits on the Mid-Atlantic ridge, so there is quite a significant presence of volcanic and geothermal activity across the island. But crucially, there are two types of geothermal systems—high temperature and low temperature. High temperature systems, which can be volcanic, are connected to magma systems. In Reykjavík, we have low temperature systems. So while there is some geothermal activity, it’s simply from the warm rocks below the capital, and not directly connected to any magma systems. This means that there’s effectively no risk of an eruption in Reykjavík.

But this doesn’t mean that Reykjavík can’t be affected by volcanic activity. A volcanic eruption elsewhere on the island could have wide ranging impact, such as the closure of key roads. More directly, eruptions could occur close enough to bring lava to Reykjavík, since the nearby Reykjanes peninsula, the location of Keflavik Airport, is a potentially volcanic region. This risk is small—there’s been no volcanic activity there since the 1300s—but it could happen. So, while there’s no danger from volcanic activity in Reykjavík, that doesn’t mean volcanic activity elsewhere won’t have an effect. Of course, Iceland is pretty well prepared for such things.

Read more articles about eruptions and volcanoes here, and read more of our “Ask A…” series, in which we pose THE REALLY IMPORTANT TOUGH QUESTIONS like “Could Reykjavík erupt?” to all kind of very patient experts, here. Have a question you’d like answered? Email grapevine@grapevine.is, and you might just get an answer.