The Calbuco volcano in southern Chile erupted on 22nd April. The next day there was another large eruption. The eruptions were a surprise. Normally, there are an increasing number of earth tremors before powerful volcanic eruptions. Yet none were detected.Calbuco last erupted in 1971. The first eruption lasted for 90 minutes. It produced a large cloud of ash 20 kilometres high. Around 6,500 people who live near Calbuco were told to leave their homes. Officials set upa 20-kilometre no entry zone around the volcano. Volcanic ash in the air can damage aircraft engines. For several days after the eruption the ash caused flight cancellations and delays in Argentina and Brazil. Officials do not know when everybody will be able to return to their homes. The last time Calbuco became active, the eruption lasted for six weeks. The officials are worried about volcanic mudflows. These can be a danger when heavy rain falls on steep slopes covered in ash. Вулкан Кальбуко на юге Чили извергся 22 апр