Nasa released the first high-resolution image of a large tsunami in the Pacífico ocean captured directly from space. The phenomenon was generated by an 8.8 magnitude earthquake on the Kamchatka peninsula, in Rússia, recorded on July 29, 2025. The SWOT satellite, developed in partnership with the French space agency CNES, was able to map the waves in a band up to 120 kilometers wide.
The observations showed more complex wave patterns than those predicted by traditional models. Pesquisadores identified multiple wave fronts interacting along the path through Pacífico.
Combined data reveals greater extent of seismic rupture
Scientists from Universidade and Islândia crossed SWOT measurements with information from DART buoys spread across the ocean. The analysis indicated that the rupture of the earthquake extended for around 400 kilometers, higher than the 300 kilometers initially estimated.
The earthquake occurred in the Kuril-Kamchatka subduction zone and is among the six largest recorded since 1900. The combination of satellite and buoy data allowed us to refine our understanding of wave propagation.
SWOT technology expands vision of the ocean surface
Launched in December 2022, the SWOT satellite is designed to measure the surface height of oceans and continental water bodies on a global scale. Seus instruments can record variations with centimeter precision over wide ranges.
Before SWOT, previous satellites only captured narrow bands or isolated points during the passage of tsunamis. The new mission offers high-resolution two-dimensional images, allowing phenomena to be observed in almost real time.
Wave pattern challenges concept of non-dispersive tsunami
Tsunamis with long wavelengths are usually treated as non-dispersive waves, that is, they maintain a single shape during the ocean crossing. Images from the July event showed multiple secondary waves accompanying the main one.
- The observed dispersion suggests interaction between waves of different speeds.
- Numerical models that included dispersion showed greater agreement with real data.
- The extra energy can modulate the main wave as it approaches the coast.
The SWOT satellite captured the tsunami triggered by Russia’s Kamchatka earthquake on July 30.
— NASA Earth (@NASAEarth)September 2, 2025
By providing data on the wave’s height, shape, and direction, SWOT is helping scientists improve tsunami forecast models and protect coastal communities.https://t.co/BL8QjUrWaj pic.twitter.com/9acKXVcI6i
New paradigm for tsunami modeling
Research published in the journal The Seismic Record highlights gaps in traditional propagation models. The presence of secondary waves can change the height and impact in coastal regions far from the epicenter.
Experts highlight that SWOT data paves the way for more accurate forecasts. The ability to observe the entire wave field in real time represents a significant advance in ocean monitoring.
Potential for faster alerts
The integration of satellite images with existing buoy networks increases the reliability of forecasts. Futuras missions will be able to incorporate this data into near real-time warning systems.
The Kamchatka event demonstrated that SWOT can record tsunamis even when the mission was not specifically designed for that. Pesquisadores await new overflights to validate the results in other scenarios.
Advancement in knowledge of ocean dynamics
The case recorded the first complete map of a transoceanic tsunami generated by a subduction zone. The images revealed previously inaccessible details about the interaction of waves with Pacífico’s bathymetry.
The experience reinforces the importance of satellites dedicated to monitoring the marine surface. The data obtained in July already serves as a reference to calibrate models used in coastal civil defense systems.
