Eyjafjallajökull/Definition

A volcano in the South of Iceland which became known world-wide when it erupted in March-April 2010, causing its glaciers to melt, while producing a giant ash cloud that reached up into the stratosphere and blocked the air traffic in most of Europe for about one week; major previous eruptions took place in 920, 1612 and 1821-1823, each time followed by eruptions of the neighbouring Katla volcano, which is also sublagcial.