Volcano alert: Scientists discover a signal that could transform early warning systems
People who live near active volcanoes need alerts they can trust. False alarms wear down that trust, while missed warnings put lives at risk. Steam-driven blasts, which can erupt with few surface signs, are especially hard to predict.
Scientists are testing a signal within earthquake waves called shear-wave splitting that may help. When seismic shear waves cross cracked, stressed rock, they separate into two directions: one faster and one slower.
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Shear-wave splitting rises when cracks open in a preferred direction. It stays low when cracks are scattered or stress doesn't change much.
This makes the signal useful for spotting shifts in a volcano's hydrothermal system, where hot water and steam move through fractured rock.
At Mount Ontake in Japan, researchers installed 12 stations to monitor these changes.
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