Water is fundamental to the evolution of Earth, profoundly governing subduction dynamics and surface manifestations, including earthquakes, arc-to-intraplate magmatism, and resource formation. Despite recent advances, investigating the transport and multifaceted impacts of water from subduction initiation to the deep mantle requires bridging significant gaps in the disciplines. This session highlights the critical role of water in deep-surface coupling, using Northeast Asia—encompassing Japan, Korea, and China—as a natural laboratory. In this region, water-driven dynamics are exceptionally active from the trench to the deep continental interior. We invite interdisciplinary contributions from seismology, geochemistry, petrology, marine geology, paleomagnetism, and geodynamics. By integrating geophysics and geochemistry, we aim to foster breakthroughs in understanding how the cycling of deep water shapes the interior and surface of the planet. We highly encourage collaborative studies linking deep-Earth processes to surface phenomena.

• P - Planetary Sciences
• S - Seismology
• T - Tectonophysics
• V - Volcanology, Geochemistry and Petrology