SWOT detects dispersive tsunami tied to a near-trench source in the 2025 Kamchatka earthquake
Summary
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 magnitude 8.8 Kamchatka earthquake, the NASA/CNES Surface Water and Ocean Topography (SWOT) satellite captured a distinct train of short-wavelength tsunami waves, which we link to near-trench tsunamigenesis. Sensitivity analyses of earthquake slip indicated tsunamig
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# SWOT detects dispersive tsunami tied to a near-trench source in the 2025 Kamchatka earthquake
*Published: 2026 Mar 26*
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
magnitude 8.8 Kamchatka earthquake, the NASA/CNES Surface Water and Ocean
Topography (SWOT) satellite captured a distinct train of short-wavelength
tsunami waves, which we link to near-trench tsunamigenesis. Sensitivity analyses
of earthquake slip indicated tsunamigenesis within 10 kilometers of the trench,
an inference not attainable from land seismology and 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 constraint
on source processes, with implications for tsunami hazard science and
subduction-zone geodynamics.
DOI: 10.1126/science.aeb8634