Named after an evil troll, Katla has a larger magma chamber than Eyjafjallajokul\'s. Its last major eruption in 1918 continued more than a month, turning day into night, starving crops of sunlight and killing off some livestock. The eruption melted some of the ice-sheet covering Katla, flooding surrounding farmlands with a torrent of water that some accounts have said measured as wide as the Amazon.
Now, clusters of small earthquakes are being detected around Katla, which means an eruption could be imminent, seismologists say. The earthquakes have been growing in strength, too. After a long period of magnitude 3 tremors, a magnitude 4 quake was detected last week.
Source: http://www.usatoday.com/news/world/story/2011-10-13/iceland-katla-volcano/50750556/1
