Shear-Wave Splitting:
University of Oxford scientists have proposed a new method for monitoring volcanic eruptions using a seismic phenomenon called shear-wave splitting at Mount Ontake, Japan.Shear-wave splitting refers to the phenomenon where seismic shear waves travel at different speeds based on their polarisation, especially when passing through aligned cracks or fractures in rocks. As magma and volcanic fluids move underground, they alter stress conditions, causing cracks in surrounding rocks to open or close. These changes affect the speed and direction of shear-waves, which scientists can monitor. The degree of shear-wave splitting increases when internal pressure builds up, offering a potential early-warning signal for impending eruptions.Mount Ontake is an active stratovolcano located in Honshū Island, Central Japan, near Tokyo. It is Japan’s second-highest volcano and part of the Pacific Ring of Fire.
