Professor Geoffrey Brown, head of earth sciences at the Open University, had been attending a UN-sponsored conference on volcanoes in the town of Pasto, 13 miles from the Mount Galeras volcano. His body has not yet been identified, but the Foreign Office last night confirmed he was missing, presumed dead.
As Dr Brown and 15 other scientists measured the 14,000ft volcano's gas output next to its rim, a sudden eruption spewed steam, rocks and ashes thousands of feet into the air.
'There was no way to escape the rocks falling,' Andrew McFarlane of Florida International University, one of the participating scientists, said. 'We just ran . . I guess we were lucky.'
Professor Brown, aged 47, leaves a wife and three grown-up daughters. He was one of Britain's leading experts on volcanoes and had a key role in the Open University as chairman of its research committee. He had been working on methods of predicting eruptions based on subtle, local changes in the gravitational field. His team has had some success with the method - they predicted an eruption in Costa Rica.
Eighteen months ago three vulcanologists were among more than 30 people killed when Mount Unzen blew up in southern Japan. Among the dead on that occasion were 14 Japanese photographers and a film crew.
In Colombia, the Galeras volcano - one of 14 which are active in that country - came back to life last July after three years of inactivity. One of the four Colombian scientists who died recorded a television interview shortly before his death saying it could blow again at any time. The other victim was a Russian. The authorities have declared a yellow alert, which means the 300,000 people who could be endangered by a major eruption should be ready to leave at short notice.
The eruption happened late on Thursday, British time. The search for survivors and bodies was hampered by fog and the risk of further detonations.
Professor Brown's wife, Evelyn, is an Open University staff tutor based at the institution's Nottingham regional centre.
Also attending was Dr Peter Baxter, a Cambridge University expert on the health risks associated with volcano gases. He left the crater rim two hours before the eruption and is staying in the area to help.
Dr Chris Wilson, a colleague, said: 'We're greatly distressed. Geoff was a prolific and gifted teacher who wrote numerous Open University texts and who passionately believed in the development of its research activities.'Reuse content