A NEW discovery that challenges what we know about volcanic lava could prove to be a useful means of forecasting future eruptions.
Lava samples have shed new light on the geological make-up of the Earth's crust and a University of Queensland-led study suggests this new information could protect lives, infrastructure and crops.
UQ volcanologist Teresa Ubide said scientists had long believed cooled lava from "hot spot" volcanoes was "pristine" magma from the melting mantle, tens of kilometres under the Earth's surface.
But Dr Ubide said research indicated this belief was a result of geological deception.
"These volcanoes are extremely complex inside and filter a very different melt to the surface than what we've been expecting," Dr Ubide said.
"This is due to the volcano's intricate plumbing system that forces many minerals in the magma to crystallise."
Dr Ubide said samples indicated the chemistry of minerals were being changed as they were "recycled" by the rising magma.
"We have discovered that hot spot volcanoes filter their melts to become highly eruptible at the base of the Earth's crust, situated several kilometres below the volcano," she said.
She suggested close monitoring could indicate at which point the tipping point of the filtration process occurred, triggering eruptions.
"Our results support the notion that detection of magma at the crust-mantle boundary could indicate an upcoming eruption."
The international research team analysed rock samples from the island of El Hierro in Spain's Canary Islands.
Data was combined with previously published data from the island, including geochemical data from underwater eruptions in 2011 and 2012.
Findings were then tested against data collated from volcanoes around the world.
Dr Ubide said hot spot volcanoes were also found in Australia - and unlike most other volcanoes that occurred due to the collision of tectonic plates, could "pop up anywhere".
She said hot spot volcanoes such as the Glass House Mountains in south-east Queensland and the Tweed shield volcano in north-eastern NSW were active millions of years ago.
"They produced enormous volumes of magma and make excellent laboratories to explore the roots of volcanism.
"There are even dormant volcanoes in South Australia that could erupt with little warning, that would benefit from better geological markers for early detection."
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