SERNAGEOMIN reported that Chaitén erupted on 2 May, following increased seismicity in the region the day before. A pulsating white to gray ash plume rose to an estimated altitude greater than 21 km (68,900 ft) a.s.l. and drifted SSE. The Alert Level was raised to Red. Based on observations of satellite imagery and pilot reports, the Buenos Aires VAAC reported an ash plume at altitudes of 13.7-16.8 km (45,000-55,000 ft) a.s.l. drifted NE. According to news articles, Chile’s government declared a state of emergency on 2 May and several hundred people were evacuated from the town of Chaitén (10 km SE). The eruption was initially thought to have been from Minchinmávida, about 17 km ENE, which last erupted in 1835.
According to news sources, ashfall was reported during 2-6 May both locally and up to hundreds of kilometers away, affecting water supplies and roads. Based on observations of satellite imagery and pilot reports, the Buenos Aires VAAC reported that during 3-6 May ash plume rose to altitudes of 7-10.7 km (23,000-35,000 ft) a.s.l. and drifted SE, E, W, and NE. News sources indicated that about 4,000-5,000 people were evacuated from the town of Chaitén and surrounding areas as the eruption continued. On 5 May, ONEMI (Oficina Nacional de Emergencia – Ministerio del Interior) reported that evacuations took place in Futaleufú, about 65 km ESE, where about 30 cm of ash accumulated. One elderly person died during the evacuation efforts. On 6 May, ONEMI and SERNAGEOMIN reported that the eruption became more forceful and generated a wider and darker gray ash plume to an estimated altitude of 30 km (98,400 ft) a.s.l. All remaining people in Chaitén were ordered to evacuate, as well as anyone within 50 km of the volcano.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Oficina Nacional de Emergencia – Ministerio del Interior (ONEMI), Buenos Aires Volcanic Ash Advisory Center (VAAC), Associated Press, Agence France-Presse – “Report provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”