Two years ago this month and Eyjafjallajokull, the unpronouncible Icelandic volcano, blew it's stack.
Scientists were worried then that neighbouring Katla caldera would also erupt and two years on, it's rumbling with erratic movements of the surface and bursts of earthquake activity beneath the caldera.
Katla's eruption in 1918 produced five times as much ash as the 2010 Eyjafjallajokull one. Last July, a flood of water burst from beneath the ice cap indicating that an extra pulse of heat from magma had reached the base of the ice.
Since Iceland was settled in the 9th Century, Katla has erupted nearly every 60 years but no significant event since 1918 and usually an eruption follows any eruption of Eyjafjallajokull within months. It seems it's well overdue.