EUROPE'S largest glacier, sitting on an active volcano, buckled yesterday, sending a torrent of water and ice on to an uninhabited plain in south-east Iceland.
Scientists had predicted the vast outpouring from a sub-glacial lake swollen by last month's eruption below the Vatnajokul ice cap, but they said it was faster and more violent than expected.
Dr Arni Snorrason, an expert on hydrology, was measuring river levels at the foot of the glacier when the floods began around 8 p.m. Irish time yesterday. Black water and ice swept across the remote, treeless plain.
"We had to run for our lives when it broke through. It's picking up speed much faster than we expected," Dr Snorrason told National Icelandic Radio. "We are facing the worst of the possibilities we imagined beforehand."
Pressure under the Vatnajokul glacier had been building since the volcano erupted in early October, bursting the glacier and pouring out a column of ash and steam up to six miles high.
The eruption melted part of the ice cap, filling the sub-glacial Grimsvotn lake to bursting point. Most recent estimates put the volume of melt water collected in Grimsvotn at over 3,000 billion cubic litres.
The volcano went quiet in mid-October, but the island has remained on alert for massive flooding, which could cut the country's only coastal ring road and bridges and power and telecommunication lines passing through the area.
Mr Stefan Benediktsson, warden at the Skaftafell Nature Park, said he could see huge blocks of ice flowing down on to the black sand plains. "I'm looking at an enormous iceberg of several dozen tonnes being hurled down the sands at enormous speed. You would never believe an iceberg of this size could be carried this far," he said.
Icelandic Radio said a bridge over the Gigjukvis river has already been destroyed by the black, sulphurous torrent.