Eyjafjallajökull, Iceland

This year eruptions at Eyjafjallajökull in Iceland caused unprecedented disruption to flights across the UK and Europe. A series of eruptions began March 20, 2010, but it was the dense plume of ash emitted from an eruption that began April 14 that caused the almost complete closure of European airspace. The plume rose to about 9 kilometres in the air, which made for some dramatic skies as the dust particles scattered light from the setting sun.