Predicting How Volcanoes Will Erupt May Save Millions Of Lives
An estimated 500 million people live on or close to volcanoes, and they put their lives at risk each day, as there's always a possibility that the volcanoes will erupt. A new study from volcanologists at the University of Liverpool, however, may help in predicting the way an eruption will emerge, thus hoping to reduce the extent of the damage.
The researchers discovered that a process called frictional melt determines how a volcano will erupt. It's based on the idea that magma moving upward must get through various pathways in volcano walls, while also overcoming any obstacles it faces along the way.
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Frictional melt occurs in lava dome volcanoes when magma and rocks melt from the intense heat they generated when rubbing against each other. This creates a stop-and-start kind of movement for the magma, known as a slip. The magma moves upward when pressure builds up underneath the slip, eventually breaking it - this process is called stick-slip.
"Seismologists have long known that frictional melting takes place when large tectonic earthquakes occur," lead researcher Dr. Jackie Kendrick said in a press release. "It is also thought that the stick-slip process that frictional melting generates is concurrent to 'seismic drumbeats,' which are the regular, rhythmic small earthquakes which have been recently found to accompany large volcanic eruptions."
"Using friction experiments we have shown that the extent of frictional melting depends on the composition of the rock and magma," she continued, "which determines how fast or slow the magma travels to the surface during the eruption."
An analysis of lava collected from Mount St. Helens in Washington and the Soufrière Hills volcano in Montserrat revealed remnants of pseudotachylyte, a cooled frictional melt generally found along fault surfaces. The researchers concluded that the friction melt took place in the conduit, a passage through which lava flows on its way up.
"The closer we get to understanding the way magma behaves, the closer we will get to the ultimate goal: predicting volcanic activity when unrest begins," Kendrick said in the release.
"Whilst we can reasonably predict when a volcanic eruption is about to happen, this new knowledge will help us to predict how the eruption will behave. With a rapidly growing population inhabiting the flanks of active volcanoes, understanding the behavior of lava domes becomes an increasing challenge for volcanologists."
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