JpGU-AGU Joint Meeting 2026

convener:Kazutaka Mannen(Hot Springs Research Institute of Kanagawa Prefecture), Isoji Miyagi(The National Institute of Advanced Industrial Science and Technology), Noriyoshi Tsuchiya(National Institute of Technology, Hachinohe College), John C Eichelberger(Alaska Division of Geological and Geophysical Surveys), Jeffrey Hedenquist(University of Ottawa), Chairperson:Uno Masaoki(Department of Earth and Planetary Science, Graduate School of Science, the University of Tokyo), Farquharson Ian Jamie(Niigata University)

One of the major goals of volcanology is the prediction of eruptions, including those of magma-related hydrothermal systems. By better understanding the processes within shallow magma bodies and their associated hydrothermal systems, which at times erupt due to pressure transients, and the short-term variations (e.g., pressure, over months to years) in the hydrothermal system, it may become possible to respond in an appropriate manner. This session will examine the behavior of magma-hydrothermal systems by integrating evidence from petrological studies; from scientific and geothermal drilling; from analyses of ore deposits; and from volcanic-gas research. To deepen understanding of magma-hydrothermal system behavior, we welcome conceptual and theoretical contributions and case studies on eruption control in magma-hydrothermal systems and on the utilization of these systems as sources of energy and mineral resources, together with evaluations of their potential side effects. We will also discuss the technical challenges involved in drilling into active magma-hydrothermal systems for the purpose of gathering information on their physical and chemical conditions and changes. We welcome discussions of deeper crustal processes relevant to unrest, such as deep low-frequency earthquakes and metamorphic dehydration, where they inform the behavior of shallow magma-hydrothermal systems. Beyond hazard mitigation, this session also aims to bridge volcanology, geothermal science and engineering, and economic geology, domains that are naturally contiguous but have not been sufficiently integrated, in order to deepen mutual understanding and collaboration.