INTENSE seismic activity rumbled on in a volcano erupting under Europe's largest glacier yesterday, but atrocious weather prevented Icelandic scientists from viewing a column of smoke and gas.
Seismologists also noticed earthquake activity at another volcano some 1,000 metres under the glacier. Several volcanoes are buried under the ice.
A gigantic lake of glacier water - melted by the volcano is building up under the icecap and scientists predict it will soon burst through the glacier and flood large areas of remote and mainly uninhabited eastern Iceland.
The eruption burst through the remote Vatnajokul glacier in the south east of the island on Wednesday, creating an ice fissure 10 km long.
The volcano spewed a column of ash and steam into the sky and ash began settling in villages in the north and east of the country on Sunday.
Scientists said the longer they have to wait for the glacier to burst the worse the environmental damage will be.
Engineers braved rain and galeforce winds to try to detect the first signs that vast quantities of water were about to burst from a sub glacial lake filled to the brim by the eruption.
"It's like giving birth to a child. You know it's coming, but not when," said Mr Einer Haflidasson, chief engineer for the lcelandic Public Roads Administration.
As the glacial ice melted in the intense heat of the eruption, radar measurements indicated that water levels in the sub glacial Grimsvotn lake had risen a further 10 metres to around 1,480 metres.
The increasing pressure implies that the glacier's ice cap must eventually be forced off, releasing water from the sub glacial lake, parts of the glacier and debris from the eruption in a torrential stream.