Calbuco Erupts

Calbuco, located in southern Chile erupted without warning on 22 April 2015 leading to the evacuation of thousands of people. The volcano has a summit of 2003m (elevation: 6570ft) and is one of the most active volcano in the region.

Two confirmed VEI 5 eruptions have taken place in the past, dated 8460 (+/-155) and 6760 (+/-825) and six VEI 4 eruptions have also taken place. The last eruption was a VEI 2 on 26 August 1972.

On 22 April an hour before the first eruption volcano-seismic activity was detected, of which the largest occurred at 17:35. At 18:04 Calbuco erupted spectacularly sending a sub-Plinian ash column 15 km into the atmosphere. The ash column travelled north, northwest and east from Calbuco. The eruption lasted 90 minutes and authorities raised the Alert Level to Red and placed a 20 km exclusion zone around the volcano.

On 23 April at 01:00 a second larger eruption took place, generating a sub-Plinian ash column over 15 km into the atmosphere. The eruption lasted six hours and the ash column travelled north and east from Calbuco. According to the Global Volcanism Program, six vents on west, southwest, and south of the old lava dome were the source of the ash emissions.

SERNAGEOMIN estimated 210 million cubic metres (7420 million cubic feet) of ash has been emitted during the eruptions. An estimated 0.3-0.4Tg of sulphur dioxide emissions was also detected 21 km into the atmosphere on 28 April.

Lava bombs, including incandescent tephra were ejected within a distance of 5 km during the eruptions and pyroclastic density currents generated by the eruption travelled a distance of 7 km. Lahars travelled a distance of 15 km.

A total of 6514 people in the town of Puerto Montt and regions of Lago Chapo, Chamiza and Correntosowithin the 20 km exclusion zone were evacuated and are currently living in temporary shelters. Fortunately no fatalities or injuries have been reported.

Cities and towns as far away as 70 miles, including those in Argentina located north east of Calbuco have experienced ash falls. Buildings, rivers, farms, infrastructure including roads have all been covered by tephra. Roofs of a few buildings in the vicinity of the volcano have collapsed due to the weight of tephra.

Animals have also suffered due to the eruption and the fishing industry has faced substantial losses. The eruption also caused disruption to international flights across cities and led to the cancellation or delay.

After the two large eruptions, the Alert Level remained Red due to the emission of smaller ash columns reaching heights of less than 2 km and volcano-seismicity. Although a few residents were allowed in and out to collect personal belongings the exclusion zone remains. Lahars continue to pose a risk and residents are strongly advised to stay away from the vulnerable exclusion zone in particular 200 m around the volcano.

On 30 April at 13:09 Calbuco has begun to erupt for the third time and is currently continuing to erupt. The current eruption is less powerful than the other two and the ash column has erupted less than 5 km into the atmosphere. Further updates on the eruption will be posted when information becomes available.

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