On Saturday, a volcano in the Puyehue-Cordon Caulle chain of south-central Chile erupted after lying dormant for more than 50 years. The government evacuated several thousand residents as Puyehue threw ash more than 6 miles (10 km) into the sky, pushing the plume toward neighboring Argentina. Authorities had already put the area around the volcano on alert after a flurry of earthquakes earlier on Saturday -- at one point, the tremors reached an average of 230 per hour.