"When and where the next eruption will occur is unknown," says Jozua van Otterloo. "Although statistics tell us it could be a long time before the next eruption, the main hazard is that when it does, we will only have a few days warning." (Credit: David Hewett/Flickr)

In Australia, volcano’s past sounds alarm about next eruption

If the Mount Gambier volcano in Australia were to erupt with the same magnitude that it did 5,000 years ago, it’s impact would reach as far as 60 miles away from the eruption site.

Scientists used 3D geometrical computer modeling and thermodynamics—the study of the relationship between different forms of energy—to determine the size and magnitude of the Mount Gambier eruption.

It is believed to be the first time the magnitude and size of a volcano on Australian mainland has been calculated, based on volume estimates of the volcanic deposits, and modeling of the volcanic plume, ash-dispersal, and thermodynamics.

Australia’s most recently active volcano registered as a size four eruption on the Volcanic Explosivity Index (VEI)—a similar size to the Eyjafjallajökull, Iceland eruption in 2010, which caused global chaos. Australia could face the same scale of tragedy if a volcano west of Melbourne was to erupt.

“Little is known about the magnitude of eruptions from this volcanic province (the Newer Volcanics) that stretches around 400 kilometers between Melbourne and Mount Gambier,” says Jozua van Otterloo of the School of Geosciences at Monash University. “It has over 400 eruption centers and has been active for at least 4 to 5 million years.

“Normally the size and magnitude of eruptions of active volcanoes are determined based on observations during these eruptions. Using 3D geometrical modeling, we’ve shown it is also possible to obtain volume estimates for different deposits of a prehistoric, monogenetic volcanic center.”

130,000 Olympic pools

For the study, published in the Bulletin of Volcanology, the team produced a diagram showing the impact of ash plume as it dispersed from the 2010 Iceland eruption over Europe, but juxtaposed over Australia with the eruption in Mount Gambier.

It was shown that the amount of material dispersed during the Mount Gambier eruption was equivalent to the volume of 130,000 Olympic pools.

“Magma rose to the surface from a depth of 80 kilometers (50 miles) and a large part of that magma interacted with the shallow groundwater which made the eruption so violent. With an ash plume of at least 5 to 10 kilometers (3 to 6 miles) high, the eruption can be classified as a size four eruption on the Volcanic Explosivity Index (VEI),” van Otterloo says.

“When and where the next eruption will occur is unknown. That is why our team continues undertaking extensive research in the area. Although statistics tell us it could be a long time before the next eruption, the main hazard is that when it does, we will only have a few days warning.”

A similar eruption in the region would cause closure of the major airspace of eastern Australia, health risks from fine ash composed of glass fragments, destruction of crops, and impacts on livestock up to 100 kilometers (62 miles) from the erupting site and disruption to local infrastructure, van Otterloo says.

“Understanding explosive volcanism aids the community to manage risk and provides insight into potential regional or global disruptions including to infrastructure, and impact on climate.”

Source: Monash University

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  1. AusEng

    Very interesting but stating an outdated, imperial figure in the first paragraph is very distracting. Why couldn’t it have read ’100km’? Last time I looked Monash University is in Australia and science uses the metric system.

  2. Timothy N.

    Historical evidence: one volcanic eruption would suffice to cause global volcanic winter.
    One volcanic eruption would be sufficient to cause a region to drop few degree of temperature and causing food crop fail with acid rain. This happened before in other region. Historical evidence:

    Global Cooling: 1815-1817 in New Hampshire
    In April 1815 Mount Timboro erupted in the East Indies. A vast layer of volcanic ash soon encircled the earth, cooling the northern hemisphere by an average five degrees Fahrenheit for the next several years. In 1816 the mean temperature in London was fifty-six degrees; plays and books were written about the new weather pattern by Lord Byron and other famous authors of the day.

    On the farms of the former British North American colonies, and in New Hampshire, agricultural production was particularly hard hit by climate cooling.

  3. jamal

    volcano erupting every afew thousands years not every 700,000 years. Carbon dating is totally inaccurate.This is from nature magazine

    The carbon clock is getting reset. Climate records from a Japanese lake are set to improve the accuracy of the dating technique, which could help to shed light on archaeological mysteries such as why Neanderthals became extinct.
    Carbon dating is used to work out the age of organic material — in effect, any living thing. The technique hinges on carbon-14, a radioactive isotope of the element that, unlike other more stable forms of carbon, decays away at a steady rate. Organisms capture a certain amount of carbon-14 from the atmosphere when they are alive. By measuring the ratio of the radio isotope to non-radioactive carbon, the amount of carbon-14 decay can be worked out, thereby giving an age for the specimen in question.
    But that assumes that the amount of carbon-14 in the atmosphere was constant — any variation would speed up or slow down the clock. The clock was initially calibrated by dating objects of known age such as Egyptian mummies and bread from Pompeii; work that won Willard Libby the 1960 Nobel Prize in Chemistry. But even he “realized that there probably would be variation”, says Christopher Bronk Ramsey, a geochronologist at the University of Oxford, UK, who led the latest work, published today in Science. Various geologic, atmospheric and solar processes can influence atmospheric carbon-14 levels.
    However,Radioactive decay rates vary with the sun’s magnetic field intensity. This fact has already been observed but it is not yet understood. I have explained it in my book.Thus during the time when the earth changes its magnetic radioactive decay rates increases

  4. Hans Geiger

    Who comes up with Millions of years is wrong already, no need to read on.

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