In a landmark achievement for disaster preparedness, the U.S.-French SWOT (Surface Water and Ocean Topography) satellite has successfully captured the leading edge of a tsunami wave in the Pacific Ocean. The groundbreaking observation was made on July 30, 2025, just 70 minutes after a powerful magnitude 8.8 earthquake struck Russia’s Kamchatka Peninsula. This unprecedented data, collected in open water, is expected to significantly enhance operational tsunami forecasting.
The SWOT satellite, a joint venture between NASA and the French space agency CNES, is specifically designed to map the Earth’s oceans and freshwater bodies. It is equipped with advanced technology, including the Ka-band Radar Interferometer (KaRIn) instrument provided by NASA and a dual frequency Poseidon altimeter from CNES. This specialized radar allows SWOT to measure the height of the ocean’s surface with incredible accuracy.
In this instance, SWOT’s measurements showed the leading edge of the tsunami wave to be approximately 1.5 feet (45 centimeters) high as it traveled through the deep ocean. Crucially, the satellite also captured the wave’s profile and direction, providing a detailed picture of the tsunami’s journey toward coastal areas.
The implications of this data are profound. Scientists at the NOAA (National Oceanic and Atmospheric Administration) Center for Tsunami Research immediately tested their forecast models using SWOT’s new data. They found that incorporating these measurements could dramatically improve the accuracy of their predictions.
NASA oceanographer Ben Hamlington emphasized the importance of this early detection, noting that a seemingly small 1.5-foot wave in the deep ocean can amplify into a destructive 30-foot wave upon reaching the shallow waters of the coast. Vasily Titov, chief scientist at the NOAA Center for Tsunami Research, highlighted that this capability has been a long-sought goal since the devastating 2004 Sumatra tsunami, which killed hundreds of thousands of people.
The successful observation by SWOT marks a significant leap forward in our ability to monitor and forecast tsunamis. By providing real-time, high-resolution data on a tsunami’s characteristics in the open ocean, the satellite has opened the door to more accurate and timely warnings, ultimately helping to save lives and protect coastal communities from future disasters.