Over two-thirds of Earth’s surface and eighty percent of plate boundaries lie beneath the oceans, limiting the direct application of space geodesy to measure seafloor motion and deformation. Yet many critical Earth processes and infrastructure are offshore, including sources of major earthquakes and tsunamis, submarine volcanoes and landslides, and hydrocarbon production systems, all of which require geodetic monitoring. Despite technical and logistical challenges, seafloor geodesy is rapidly advancing to address a key gap in the global observing system. Innovations in instrumentation, autonomous platforms, and data processing are improving spatial coverage, temporal resolution, and positioning accuracy. This session invites contributions across the full spectrum of seafloor geodesy, from technology development to scientific and engineering applications. We welcome advances in instrument design, network configuration, calibration, noise characterization, data integration, and near-real-time capability, as well as studies of offshore deformation processes and emerging engineering applications such as infrastructure monitoring.

• NH - Natural Hazards
• OS - Ocean Sciences
• S - Seismology
• T - Tectonophysics