Above a geological hotspot, deep inside the earth, where plumes of hot material can well upwards. The last eruptions were in the 1200s, lasting for decades, but then nothing for 800 years, until five eruptions that started in march 2021. So why was there such a Big Gap . Over geological time, the Tectonic Plates are pulling it apart at about the speed your Finger Nails grow, so a few centimetres every year, but they dont seem to smoothly pull apart, they go through pulses of higher activity, and this is likely what we are seeing right now. In 2010, in the south of the country, another eruption generated a giant ash cloud. It exploded through an Ice Sheet which pulverised the ash into an even finer material, disrupting Air Travel across europe. It is unlikely the same thing will happen now. There is no glacier here