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26 May 2025

New scientific discovery can lead to better volcano early warning systems

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Oxford researchers are exploring a new volcano warning system that detects changes in shear-wave splitting to predict eruptions, according to Scitechdaily.com. 

In a new study, researchers from the University of Oxford examined a seismic phenomenon called shear-wave splitting as a potential tool for providing early warnings of dangerous eruptions.

Their study analyzed seismic signals from two eruptions of Japan’s Ontake Volcano—one small and one explosive—and found that shear-wave splitting varied based on eruption size. 

The researchers were thrilled to find that during the smaller eruption, shear-wave splitting stayed consistent. However, in the larger 2014 eruption, the splitting dramatically increased—doubling just before Ontake erupted. This led them to conclude that the greater stress levels during the major event intensified the splitting, hinting at a valuable connection between splitting patterns and eruption magnitude.

Shear-wave splitting occurs when seismic shear waves move at different speeds depending on the geology they travel through. Cracks and fractures within rock formations influence wave movement, slowing those that travel across them while allowing others to pass more freely. If these cracks are consistently aligned, the splitting effect becomes more pronounced.

Beneath a volcano, magma and fluids create stress that alters the surrounding rock, causing cracks to open or close in specific directions. Scientists use changes in shear-wave splitting over time to track these shifts, helping them understand underground activity. 

This discovery could potentially improve early warning systems, helping communities prepare for hazardous volcanic activity. 

 

Photo Credit: Wikipedia Creative Commons License 

October 7, 2014 after the September 27, 2014 Mount Ontake eruption, Mount Ontake seen from Nōbi Plain, in Aichi prefecture, Japan.

Author: Alpsdake