© J. AleanAksja
A volcano expert warned yesterday that another Icelandic eruption could be imminent, raising the prospect of summer holiday flight chaos.

Dr Hazel Rymer has been monitoring a volcano called Askja 180 miles north of Eyjafjallajokull - the volcano that caused a complete shutdown of most of Europe's airspace in April.

She says it is showing increasing signs of seismic activity. Her team from the Open University in London and volunteers from environmental charity Earthwatch have noticed changes in the "plumbing system" beneath the mountain.

Dr Rymer said: "New magma is accumulating. This is what happens before an eruption, but a critical amount needs to accumulate and we cannot say what that is. We can't predict when an eruption will occur - it could be next week or next year."

Askja, which is on the same tectonic plate as Eyjafjallajokull, last erupted in 1961. For the past few centuries it has erupted every 40 years or so. In 1875 Askja had a major eruption causing a crater three miles wide and sending ash as far as Scotland and Scandinavia.

Dr Rymer doesn't think the recent Eyjafjallajokull eruptions could be causing activity at Askja. European airspace was closed from April 15 to 20, grounding about 10 million travellers and costing the airline industry an estimated £1.2billion.