Eruption at Chaitén volcano, Chile

Chaitén volcano in southern Chile is currently erupting, causing a major alert across neighbouring regions of Chile and Argentina. Up to 1500 people have so far been evacuated from the nearest large town, also called Chaitén, and nearby villages.

Chaitén volcano is in Los Lagos region, and is approximately 1200 kilometres south of the Chilean capital, Santiago. From the Servicio Nacional de Geología y Minería de Chile (SERNAGEOMIN) bulletin, 2 May 2008:

Chaitén volcano began an eruptive cycle in the early hours of 2 May characterized by the continual emission of ash. The first overflight this morning observed the presence of a dense eruptive column of a white to grey colour with a height estimated as more than 20 kilometres. This column consists of a plume of particulate matter with an axis of dispersion approximately SSE according to the prevailing winds. … There is no ice cover at the volcano so lahars (volcanic floods) are not in this case an imminent danger. However, the explosive nature of the eruptive cycle suggests scenarios of the fall of pyroclastic material possibly of considerable thickness in the surrounding area, and the occurrence of pyrocastic flows associated with the collapse of the dome cannot be ruled out.

SERNAGEOMIN spokesman Luis Lara is reported as saying that this eruption ‘appears to be more intense than that of Llaima‘. Bulletins from the Buenos Aires VAAC report that the eruption plume has reached altitudes of between 13.7 and 16.7 kilometres. Ash fall from the eruption column is taking place in neighbouring areas of both Chile and Argentina.

Chaitén volcano was not initially identified as the location of the eruption because of poor visibility in the area. The first reports named Chaitén’s much bigger neighbour Minchinmávida as the erupting volcano, and it was not until the SERNAGEOMIN overflight this morning that the eruption was definitely located at Chaitén. As AFP reports, ‘This makes the emergency more complicated, since the volcano Chaitén is located much closer to a town of the same name, unlike Minchinmávida, which is about 35 km away … Chaitén volcano is located about 10km from the town of Chaitén, which has some 7000 inhabitants’. The Smithsonian Institution’s Global Volcanism Program describes Chaitén volcano as ‘a small, glacier-free late-Pleistocene caldera with a Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf of Corcovado’ with a most recent known eruption dated at 7420 BC ± 75 years.

The Chilean Government Emergencies Office ONEMI declared a red alert for the town of Chaitén at 14:00 local time on 2 May. ONEMI further reports that an evacuation has begun of 1500 people from the town to shelters at Castro and Puerto Montt, with priority being given to vulnerable groups such as the sick, the elderly and pregnant women, and that the town’s supply of drinking water has been suspended because of the danger of contamination from volcanic ash, with emergency water supplies being brought in by truck. Army, Navy, Air Force, Police, Firefighters, municipal and provincial government are all active in the relief effort, supported (says another ONEMI bulletin) by two ships, six patrol boats, a C-130 aircraft and four helicopters.

ONEMI update – in a new bulletin issued on 3 May 2008 ONEMI reports that under the auspices of the Chilean Navy 1221 people have so far been evacuated from Chaitén, with another 500 due to be evacuated later today. Further evacuations, using ships with a total capacity of over 1000 persons, are planned for tomorrow. Additional drinking water for Chaitén will arrive tomorrow in a Navy tanker and a barge, and water will be provided by truck to the Futaleufu and Palena districts, which are also without potable water supplies.

The director of ONEMI, Carmen Fernández, has told Chilean national television that it is difficult to predict the future course of the eruption, reports El Mercurio: ‘We do not know how it is going to develop because … volcanic eruptions are a little erratic in their behaviour, and there is no historical record of recent volcanic eruptions at Chaitén’. There is no doubt that the eruption of this previously inconspicuous and well-behaved caldera has taken everyone by surprise.

For all our Chaitén coverage: Chaitén << The Volcanism Blog

Information
Global Volcanism Program: Chaitén – summary information for Chaitén (1508-41)
Oficina Nacional de Emergencia – Chilean government emergencies office (Spanish)
SERNAGEOMIN – volcanology information from the Servicio Nacional de Geología y Minería, Chile (Spanish)

News
Emergencia en sur de Chile y Argentina por erupción de volcán – AFP, 2 May 2008 (Spanish)
Sernageomin: Escasa visibilidad provocó la confusión de volcanes – El Mercurio, 2 May 2008 (Spanish)
Sernageomin: ‘Esta erupción parece ser más intensa que la del Llaima’ – Radio Infinita, 2 May 2008 (Spanish)
Cenizas de volcán chileno invadieron a Chubut – 26 Noticias, 2 May 2008 (Spanish)
Alarma por volcán en Chile – BBC Mundo, 2 May 2008 (Spanish)
Chilean volcano forces evacuation – Reuters UK, 2 May 2008
Chile volcano erupts, villages evacuated – Associated Press, 2 May 2008
Chile volcano prompts evacuation – BBC, 3 May 2008
Directora de la Onemi: No sabemos cómo va a evolucionar el volcán – El Mercurio, 3 May 2008 (Spanish)