The million króna question — why is Iceland so explosive? — has a fairly straight-forward answer. Iceland is located on the Mid-Atlantic Ridge. So if you think back to grade school science class when you learned about all those land masses floating like plates on the surface of the Earth, constantly colliding with one another, Iceland straddles two of those plates.
More specifically, Iceland sits on both the North American Plate and the Eurasian Plate, with the meeting point of the two in Iceland being the Reykjanes Ridge in the south and the Kolbeinsey Ridge in the north.
That means there are a lot of points in Iceland’s four major volcanic zones where shifting plates can make way for the Earth to relieve a little pressure, let off some steam or spew some lava.
Iceland is home to 49 named volcanoes, but just 18 of those have erupted since the time of the settlement around the year 874. Those 18 have, to varying degrees, been fairly active, though, with an eruption occurring roughly every five years.
While an eruption in Iceland may only occur every five years, a more chronic symptom of living between tectonic plates is near constant earthquakes — just take a peek at the Icelandic Met Office's near real-time map of quakes for an idea of just how constant they are. That doesn't mean we're always feeling them, though.
Residents of the Reykjanes peninsula were in for a bumpy ride for much of 2021 as near constant earth and aftershocks preceded the magnificent eruption at Fagradalsfjall — even us city slickers in Reykjavík got to experience some rumbles and jolts. But most quakes are usually rocking and rolling in areas where people aren’t being disturbed.