document: The volcano, which had been dormant for four decades, erupted on Wednesday, sending a plume of smoke and ash 10km (6 miles) into the sky.
  Authorities evacuated people living within a 21km (13 mile) radius.
  Road workers used lorries to plough through the ash, which lay up to a metre (3ft) deep in some places.
  As the massive ash cloud drifted south, emergency workers handed out protective masks in a wide area including parts of Chile and Argentina.
  "The ash might damage crops, animal feed, bridges, roads, people's work routines, tourism and especially their health," Michelle Bachelet, President of Chile's National Geology and Mines Service, said.
  The first eruption on Wednesday evening lasted about 90 minutes and send a huge mushroom cloud of ash into the sky.
  Seven hours later the volcano erupted again, this time shooting lava into the air and generating volcanic lightning.
  There have been no reports of deaths or injuries.
summary: Residents and emergency workers in southern Chile have been clearing ash that rained down on towns after an eruption of the Calbuco volcano.