Supporting data of SWOT detects dispersive tsunami tied to near-trench tsunamigenesis in 2025 Kamchatka earthquake

Tsunamis from large subduction earthquakes pose severe coastal hazards, yet their genesis near the trench remains poorly constrained by land-based seismic–geodetic data and distant deep water sensors. Following the 29 July 2025 M8.8 Kamchatka earthquake, the SWOT satellite captured a distinct train of short-wavelength tsunami waves, which we link to near-trench tsunamigenesis. Sensitivity analyses of earthquake slip indicate tsunamigenesis within ~10 km of the trench — an inference not attainable from land geodesy or sparse deep-water seafloor pressure records alone. These results provide the first high-resolution, two-dimensional spaceborne observation directly linking the measured dispersive tsunami wavefield to near-trench tsunamigenesis, extending earlier model and gauge-based inferences. They establish SWOT as a transformative constraint on source processes, with implications for tsunami-hazard science and subduction-zone geodynamics.