December 31, 2010 – A new swarm of recent quakes (seen in red) have rattled some of the most dangerous volcanic glaciers in Iceland. The strongest of the tremors had a magnitude of 3.3. The Vatnajökull glacier to the north is the largest ice cap in Europe. It has a maximum density of 1000 meters. Subglacial eruptions supposedly occured under the massive glacier during the last Ice Age. The Mýrdalsjökull glacier to the south, where tremor activity has seen an uptick, is home to the deadly Katla volcano- the twin sister of Eyjafjallajökull, which erupted in April of 2010. According to geologists, Iceland is in a period of high volcanic activity which is due to last for several more decades.