Isotopic signatures link hot spring magmatic water to the subducting Pacific Plate

Water flowing from hot springs near volcanoes often contains a mixture of meteoric water that has percolated underground and a deeper component known as magmatic water. Researchers at the University of Tsukuba used numerical simulations and isotopic data to show that magmatic water in hot springs and volcanic gases around Kussharo Caldera, Hokkaido, originates from the subducting Pacific Plate, which descends from the Kuril Trench to a depth of 125 kilometers (78 miles). The paper is published in the Journal of Volcanology and Geothermal Research.