A tractor's light is covered with volcanic ash in Futaleufu, near the Chaiten volcano, located some 1,450 km (900 miles) south of Santiago, May 8, 2008. REUTERS/Jorge Cortizo
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.The eruption of ash could last for monthsAn abrupt descent would blanket vast areas with deadly hot gas, ash and molten rock, he said.






















