The Surface Water and Ocean Topography (SWOT) satellite, a joint mission between NASA and the French space agency CNES, has captured the first high-resolution images of a massive tsunami moving across the Pacific Ocean.
The satellite recorded the tsunami approximately 70 minutes after an 8.8 magnitude earthquake struck off the coast of Russia’s Kamchatka Peninsula in 2025. The data revealed that the tsunami did not travel as a single, uniform wave, but instead spread out, fragmented, and formed complex patterns across the open ocean.
According to Angel Ruiz-Angulo, lead author of the study from the University of Iceland, the SWOT satellite’s wide-swath capability allows scientists to observe tsunami behavior in unprecedented detail. “Before, with DART sensors, we could only see tsunami at specific points across the ocean,” Ruiz-Angulo said. “Now, with SWOT, we can capture areas up to around 120 kilometers with high resolution that has never existed before.”
Researchers noted the presence of secondary waves with shorter wavelengths trailing behind the main tsunami wave—a phenomenon previously difficult to detect. These findings challenge traditional models of tsunami propagation and may lead to improvements in early warning systems.
The observations were made possible by SWOT’s Ka-band Radar Interferometer (KaRIn), which provides a 120-kilometer-wide swath of sea level measurements. This technology enables a two-dimensional view of tsunami wavefields, offering a more complete picture than earlier point-based sensors.
Understanding how tsunamis evolve in the deep ocean is critical for coastal preparedness. More accurate models based on real-world data like that from SWOT could facilitate authorities issue timely warnings and protect vulnerable communities from future tsunami threats.
