A recent The Seismic Record study, "SWOT Satellite Altimetry Observations and Source Model for the Tsunami from the 2025 M 8.8 Kamchatka Earthquake", has made international headlines by presenting the first high-resolution spaceborne observation of a major earthquake-generated tsunami captured by NASA and CNES’s SWOT (Surface Water and Ocean Topography) satellite. The tsunami followed a magnitude 8.8 megathrust earthquake off Russia’s Kamchatka Peninsula on 29–30 July 2025, the six strongest earthquakes ever recorded by modern seismic instruments.
An international team of SWOT tsunami–earthquake researchers - led by Angel Ruiz-Angulo of the University of Iceland and Diego Melgar of the University of Oregon, with contributions from colleagues Charly de Marez, Aurélien Deniau, Francesco Nencioli, and Vala Hjörleifsdóttir (Reykjavík University) - reports that the SWOT satellite happened to pass over the Pacific Ocean about 70 minutes after the quake, capturing a wide swath of sea-surface height data that revealed the tsunami’s structure. Unlike traditional point measurements from buoy networks, SWOT’s 120-km-wide swath provided a two-dimensional snapshot of the wave height, shape, and dispersive behavior — data that had previously been unavailable at this resolution from space.
According to the researchers, these observations reveal complex dispersive wave patterns propagating across the basin, challenging the long-held assumption that great tsunamis behave as simple, non-dispersive shallow-water waves. “I think of SWOT data as a new pair of glasses,” Ruiz-Angulo said, noting that it allows scientists to see the tsunami’s evolution in space and time far beyond what single-point sensors can show.
The paper combines satellite swath measurements with deep-ocean buoy (DART) data to refine the earthquake source model and better understand how the rupture unfolded beneath the seafloor. These insights are expected to improve tsunami forecasting and hazard models, with potential implications for early warning systems used around the Pacific.
This work represents the first published research reporting detailed SWOT earthquake-tsunami observations, marking a significant advance in our ability to monitor and interpret tsunami dynamics from space.
Here is the link to the news: https://www.seismosoc.org/news/tsunami-from-massive-kamchatka-earthquake-captured-by-satellite/
The open-source paper can be found here: https://pubs.geoscienceworld.org/ssa/tsr/article/5/4/341/718867/SWOT-Satellite-Altimetry-Observations-and-Source
A short video showing how the tsunami followed a magnitude 8.8 megathrust earthquake off Russia’s Kamchatka Peninsula on 29-30 July 2025. Credit to: Diego Melgar (University of Oregon)
