Australia ‘overdue’ for volcanic eruption? 21 September 2009Posted by admin in natural hazards.
Tags: Australia, Mount Gambier, natural hazards, volcano monitoring
Is Australia ‘overdue’ for a potentially hazardous and destructive volcanic eruption?
Australia is not a continent normally associated with active volcanism: the Global Volcanism Program currently lists a grand total of ’1 Holocene volcano’, although that ‘volcano’ is the extensive Newer Volcanic Province in south-east Australia. The province stretches across 15000 sq km of the states of Victoria and South Australia, and consists of around 400 small shield volcanoes and explosive vents active from the Tertiary to the Holocene, with the most recent eruptions at Mount Gambier (PDF) dated to around 4,000-5,000 years ago.
As the example of the Newer Volcanic Province indicates, there is plenty of evidence of volcanic activity in Australia: Geoscience Australia notes that ‘Evidence for volcanism throughout geological time can be found in every [Australian] State and Territory, with extensive volcanism down the east coast during the past 60 million years’. The east coast volcanism is put down to the Australian continent moving from south to north over a hot spot, so that the youngest volcanism is found in the south. There was some volcanic activity in Queensland as recently as around 10,000 years ago. Lava flows from Toomba vent on Nulla volcano have been dated to 13,000 years ago. This eruption, along with others in recent Australian geological history in both north and south, was almost certainly witnessed by the human inhabitants of the area (PDF) and recorded in their mythology. The south-eastern Australian volcanoes are generally regarded as ‘dormant’, the northern volcanoes as ‘extinct’; but all these extinct/dormant/active labels are rather arbitrary.
The point of all this is that Australia does have a history of fairly recent volcanism. Does that mean there is a significant volcanic eruption risk that Australians should be worrying about? Prof Bernie Joyce of the University of Melbourne thinks so:
Emergency services should prepare for volcano eruptions, particularly in Victoria where one is overdue, a Melbourne geologist has warned. Associate Professor Bernie Joyce yesterday said there were about 400 volcanoes across Victoria, including some in the state’s western uplands that could erupt at any time, potentially devastating the land around them and claiming lives.
Prof Joyce warns that in north Queensland new volcanoes 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’. Australian emergency authorities need to be better prepared, he argues, taking a lead from the kind of emergency preparation, public education and information systems seen in New Zealand.
Some of Prof Joyce’s work on volcanic risks in south-eastern Australia and links to related resources can be found here, while a wider discussion of Australian volcano hazard issues is available from the remarkably comprehensive and informative website for the town of Romsey, Victoria.
[Illustration: 'Mount Gambier, Middle and Valley Lake Craters', from Julian Edmund Tenison Woods, Geological Observations in South Australia: Principally in the District South-East of Adelaide (London: Longman, Green, Longman, Roberts, & Green, 1862), facing page 230. Available via the Internet Archive.]
Volcano eruption ‘overdue’ – The Age, 21 September 2009
Australian eruption ‘overdue’ – Science Alert, 21 September 2009
Volcano warning: Australian eruption ‘overdue’ – ABC, 21 September 2009
Volcano: we’re 5000 years overdue – The Australian, 21 September 2009