Research
Pyroclastic Peril: Impacts and Short-Term Recovery Assessment of the 2008 Chaiten eruption, Chile
Members and research affiliates of the NHRC, Tom Wilson (University of Canterbury), Graham Leonard (GNS Science), Carol Stewart, and David Dewar, travelled to northern Patagonia to assess the impacts from the on-going eruption of Chaiten volcano (Chile) during January and February 2009. As the first major explosive rhyolitic eruption in over 50 years (eruptions are typically large but infrequent), this was a highly unique and important opportunity to record and analyse the impacts and short-term recovery to an area geographically, climatically, and ecologically similar to New Zealand. The eruption is similar in magnitude and physical and chemical characteristics to what is expected from a future eruption from one of New Zealand’s numerous rhyolitic volcanoes in the Taupo Volcanic Zone.
The team observed ashfalls: contaminating water supplies, causing infrastructure failure, damaging residential and commercial buildings, causing livestock deaths and coverage of feed, human health hazards, engine failure, and closure of transport networks including road and air links. Continuing ashfall and block-and-ashfall hazards and remobilisation of ash fall deposits are causing on-going problems for communities in affected areas.
The team has also begun to piece together the complex emergency response to the volcanic crisis. An example of the scale of the crisis was the highly successful evacuation of 5,000 people between 2-4 May from the town of Chaitén and surrounding areas.
One of the key objectives of the trip included assessing health impacts from volcanic ashfall to urban and rural communities. World renowned volcanic health expert Dr. Peter Baxter from Cambridge University was a welcome addition the multi-national collaborative project, which included scientists from Chile and Argentina.
The team will now begin the mammoth task of collating and analysing the many field notes, interview data, visual images, and collected reports. The large collections of soil, vegetation and water samples will be analysed in various laboratories to add to the mountain of data collected from the trip.
The outcomes from the trip will lead to a much greater understanding of how communities and infrastructure providers manage and cope with impacts from a rhyolitic eruption. Valuable insights were also learnt in rapid evacuation planning, execution and management during a major volcanic crisis and potential health effects which may be sustained by communities from a rhyolitic eruption.
Satellite image showing ash being dispersed across southern Chile and Argentina from the May 2008 eruption of Vulcan Chaiten (NASA).