Mio Kawaji

Volcanic eruptions can cause not only pyroclastic flows and the ejection of volcanic rocks, but also landslides and tsunamis. Worldwide, more than 1,500 active volcanoes have the potential to produce such hazards, and about one billion people live in at-risk areas. To help reduce the impact of volcanic disasters, we attempted to predict eruptions at Sakurajima Volcano. Before an eruption, changes in volcanic activity can cause gases released from magma to dissolve into nearby groundwater and hot spring water. We therefore investigated whether hot spring water chemistry could be used as an indicator of impending eruptions. We analyzed chemical components related to volcanic gases—CO₂ and SO₂, which can increase when magma intrudes beneath Sakurajima, and HCl and HF, which are…