Recent volcanic activity at Mount Agung in eastern Bali [image credit: BBC]
Any kind of advance in understanding volcanic processes has to be welcomed. Sci-News reporting.
Tiny crystals of clinopyroxenes that form deep in volcanoes may be the key for advance warnings before volcanic eruptions, according to a team of vulcanologists from the University of Queensland, Australia, and Trinity College Dublin, Ireland.
“Our research provided new information that could lead to more effective evacuations and warning communications,” said University of Queensland vulcanologist Dr. Teresa Ubide.
“This could signal good news for the almost one in 10 people around the world who live within 100 km of an active volcano.”
Dr. Ubide and her colleague, Professor Balz Kamber, tracked eruptions, their triggers and time scales at Mount Etna, on Sicily in Italy, Europe’s most active volcano.
They used a new laser technique to examine the composition of tiny clinopyroxene crystals forming deep in the volcano. And what they discovered is that the crystals contain a memory in the form of growth layers that look similar to tree rings.
Reading the history from these layers may lead to more effective volcanic hazard monitoring, including for dormant volcanoes.
“The crystals are created when molten rock — magma — from up to 30 km beneath a volcano starts to move upwards towards the Earth’s surface,” the researchers explained.
“They are carried in the erupting magma, and they often continue to grow as they are being transported. Importantly, they also change in composition on their way to the surface.”
“They effectively ‘record’ the processes that happen deep in the volcano right before the eruption starts,” Dr. Ubide noted.
“We’ve found by studying these crystals in a specific volcano that, when new magma arrives at depth, up to 90% of the time it can trigger an eruption, and within only two weeks.”
From this, the vulcanologists hope to work out how to better monitor volcanoes — for instance, at what depths underground to look for signs of magma movement before an eruption.
Continued here.
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Study: Volcanic crystals as time capsules of eruption history
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January 24, 2018 at 09:57AM
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