A cloud of ash billowing from Puyehue volcano near Osorno in southern Chile, 870 km south of Santiago, on June 5, 2011. Puyehue volcano erupted for the first time in half a century on June 4, 2011, prompting evacuations for 3,500 people as it sent a cloud of ash that reached Argentina. The National Service of Geology and Mining said the explosion that sparked the eruption also produced a column of gas 10 kilometers (six miles) high, hours after warning of strong seismic activity in the area.