Scientists discover supervolcano trigger that could herald humanity’s doom
Written by Iain Thomson, The Register
Turns out we may get very little warning before big bang
European scientists think they’ve found the trigger mechanism for the eruption of supervolcanoes, the most violent and dangerous natural disasters on Earth.
Around 20 supervolcanoes have been discovered under the Earth’s surface (and at least one suspected site on Mars), and when they blow the results can be catastrophic. The Lake Toba supervolcano in Indonesia erupted around 74,000 years ago and is estimated to have wiped out over two thirds of the human population at the time and dropped global temperatures by 10 degrees Celsius for a decade or more.
It had been thought that you’d need a large earthquake to set a supervolcano off, but according to new research from the European Synchrotron Radiation Facility this may not be the case. According to its paper, published in the latest issue of Nature Geoscience, that they can erupt spontaneously under their own internal pressure.
“The driving force is an additional pressure which is caused by the different densities of solid rock and liquid magma,” said lead author Wim Malfait. “It is comparable to a football filled with air under water, which is forced upwards by the denser water around it.”
The team reached this conclusion thanks to some very clever testing of how magma is formed and reacts to pressure. The boffins compressed a magma sample to 36000 atmospheres and heated it to 1700 degrees Celsius before x-raying it to monitor the flow and behavior of the molten rock.
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