Chile volcanic eruption seen at critical stage

By Antonio de la Jara

PUERTO MONTT, Chile (Reuters) - A towering plume of ash from an erupting volcano in Chile's remote Patagonia could rain down on the surrounding area and cause devastating damage, a volcano expert warned on Friday.

Luis Lara, a scientist with the government's geology and mining agency, said the column, which has soared 7.5 miles (12 km) into the air, was at a critical stage.

An abrupt descent would blanket vast areas with deadly hot gas, ash and molten rock, he said.

Authorities have evacuated thousands of people from the immediate vicinity of Chaiten volcano, 760 miles south of the capital Santiago, and are forcing people within a 30-mile (50-km) radius to leave.

Chaiten began erupting eight days ago for the first time in thousands of years.

"We are at a critical point of this phase given the characteristics (of the eruption) have remained the same for several days," Lara said.

"The volcano is now at its limit and one possibility is that the column could collapse quickly, generating flows of ... material down its ravines," he said.

The column might descend gradually and do little damage. But in the worst-case scenario, the ash and fiery material would engulf the town of Chaiten, just 6 miles from the volcano, and the areas around it.