South American eruption reveals lessons for NZ

South American eruption reveals lessons for NZ

New Zealand could learn vital lessons from how Chile and Argentina dealt with the volcanic eruption of Puyehue-Cordón Caulle last year, according to University of Canterbury’s Dr Thomas Wilson.

Dr Wilson, with Dr Carol Stewart (Joint Centre for Disaster Research) and postgraduate student Heather Bickerton (Geological Sciences) recently led an international team that studied the effects of the June 2011 eruption.

The team included colleagues from Cambridge University, UK, and the University of Comahue, in Bariloche, Argentina. The project was funded by the New Zealand Natural Hazards Platform.

“Southern Chile and Argentina are very similar to New Zealand in terms of climate and landscape so we wanted to see the impact the eruption had on agriculture, infrastructure and health, as well as assessing how Chile and Argentina managed the eruption and ways we can learn from that in New Zealand,” Dr Wilson says.

“A large volcanic eruption, which could happen in New Zealand, will deposit large quantities of volcanic ash on the landscape. In Patagonian South America, the main problem was that the strong prevailing winds remobilised the deposited ash, which prolonged the impacts by making air quality conditions unpleasant in some settlements and making conditions difficult for farming, as well as hampering efforts to clean up ash from residential areas.

“In New Zealand the higher rainfall in most areas implies that remobilisation of ash by rain would lead to problems such as blocking of rivers which may increase the risk of floods and possibly creating lahars (volcanic mudflows). This prolonging of the initial effects is not unlike a long aftershock sequence following a large earthquake - such as what we've experienced in Canterbury.”

Drs Wilson and Stewart intend to use data collected from the field trip to help create a volcanic ash analysis protocol for New Zealand, in collaboration with Massey University and GNS Science.

While in Chile and Argentina the team assessed emergency management procedures in response to the disaster.

“While individual emergency managers were highly dedicated, these individual efforts were hampered by poor coordination between agencies, “Dr Wilson says.

“There were also difficulties in how scientific information was communicated to the public, such as the likelihood of future eruptions and the health risks posed by the fine grained volcanic ash in the atmosphere and water supplies. These are good lessons for New Zealand.”

Dr Stewart says the public health response to the ash fall was not optimal and was marked by inadequate information being supplied to the population about the possible short and long term health effects of exposure to very fine, respirable volcanic ash.

“Team member Dr Peter Baxter, of Cambridge University, made extensive recommendations about research needed to investigate health effects of the ashfall, particularly on vulnerable sectors of society such as the young, elderly and those with pre-existing health problems, and also recommended measures to monitor airborne ash and to limit the entry of ash into homes and schools,” says Dr Stewart.

“Other lessons from the eruption were that a large, widespread ashfall will disrupt critical infrastructure networks, such as the electricity supply and transport networks. The city of Bariloche, an important tourist destination, suffered power outages. There were also severe effects on agriculture throughout the region, which is already struggling with long term drought conditions. Ashfall buried pastures and water supplies and local agencies have estimated that hundreds of thousands of livestock died.”

Dr Wilson says local scientists will be better prepared for future natural disasters after experiencing the Christchurch earthquakes first hand.

“As scientists, we were much more seasoned having been through a natural disaster in Christchurch, so it meant we knew what to look for in South America. It was striking to see Argentine communities, emergency managers and scientists all struggling with similar problems to what we experienced in Christchurch,” he says.

“It’s important to have reliable, well-practised and robust plans in place before an eruption, so that in the event of an eruption people and agencies are able to do the right thing at the right time for the right reasons.”

ENDS

© Scoop Media