BBC: The Calbuco volcano in southern Chile has erupted twice in the space of a few hours – having lain dormant for decades. Footage from the area shows a huge column of lava and ash being sent several kilometres into the air. The authorities have declared a red alert and evacuated more than 4,000 people within a 20km (12 mile) radius. The Calbuco volcano is one of the most active in Chile, but its eruption took officials in the area by surprise. Residents there have been warned to stay indoors. Chile has the second largest chain of volcanoes in the world after Indonesia, with about 500 that are potentially active. It is southern Chile’s second volcanic eruption in as many months. MORE