Geological Society of Australia, ScienceAlert 21 Sep 09;
A significant volcano eruption in Australia is ‘well overdue’ and emergency authorities must better prepare themselves and the wider community to respond to it, the recipient of the prestigious Geological Society of Australia (Victoria Division) Selwyn Medal for 2009 has warned.
Internationally-respected Melbourne geologist and Geological Society of Australia member, Associate Professor Bernie Joyce, will receive the Selwyn Medal this coming Thursday at the Geological Society of Australia’s (Victoria Division) annual Selwyn Symposium 2009.
“We can’t say with 100 per cent certainty that a significant volcano will strike tomorrow, next week, next year, or even 100 years down the track—but these geo-hazards are real and they must be given much more focus by emergency management authorities” Associate Professor Joyce said.
“There are around 400 volcanoes stretching from the Western District of Victoria into the Western Uplands around Ballarat and to the north of Melbourne around Kyneton and Kilmore, in some parts of the Eastern Uplands such as to the north of Benambra, and across to the South Australian border near Mt Gambier. A volcanic eruption in the Western Uplands could potentially see lava flows and ash falls impacting on Melbourne.
“There is also similar volcano risk present in various provinces in Far North Queensland, stretching from south-west of Townsville to near Cairns and up to Cooktown in the Far North. There are more than 380 volcanoes in total across this part of Queensland.
“A future eruption in any of these regions would be unlikely to come from an existing volcano (as the volcanoes there are generally considered to be 'once only’ erupters). Rather, future eruptions would occur at new sites nearby. The geological record shows that new volcanoes in these areas have erupted perhaps every 2000 years in the past 40,000 years—and given there has not been a major eruption there for the past 5000 years, a significant eruption seems well overdue.
“While any future volcanoes may discharge only small amounts of lava and ash, the real possibility remains that there could be a significant eruption — and it makes sense that the population centres potentially affected should be well-prepared for that worst-case scenario. To this end, eruption response plans should be developed and publicised by the emergency management authorities.
“It is telling that in New Zealand, which has volcano types similar to those in Australia, there is much more focus on the need to educate the public about volcano risk. For example, the Auckland Regional Council has a webpage devoted to volcano risk for that region alone, which has a history of earlier volcanoes very similar to those of Australia.
“The risk from a volcano would not just be from the initial eruption. For example, its red-hot lava and explosive ash would be a major fire hazard on the dry grassland plains of Western Victoria, and lava flows could continue for up to 20 years and for distances of more than 60 kilometres down river systems, cutting off essential water supplies and destroying infrastructure like towns, farming land, roads, railways and bridges. Ash falls could also continue for many years and an initial eruption could, in some circumstances, be followed by further volcanoes erupting near the first eruption site, affecting a wider area for a longer period.
“Eruptions can also produce a mix of toxic gases, including carbon dioxide that could collect in depressions in the surrounding land and asphyxiate those who came across it or were caught in it. An education process is needed to inform the community about how to avoid these situations if they arise.
“The geological record shows us that up to 200,000 years ago there was not a high level of volcanic activity on the Australian continent, yet during the past 40,000 years there has been a cycle of increased activity—this may be pointing to future activity.
“So it is much more likely to be a matter of when, rather than if, a significant volcano occurs in Australia, and emergency authorities should be better preparing themselves and the wider community for that eventuality.”
The Selwyn Medal is named in honour of Sir Alfred Selwyn, an eminent Victorian pioneering geologist and founder of the Geological Survey of Victoria.
In a career spanning 45 years, Associate Professor Joyce has produced significant research papers and assessments regarding volcanic risk and hazard in south-eastern Australia. He is currently studying the landforms of Western Victoria to see what they can reveal about future volcanic risk.
