New Satellite Technology Captures Unprecedented View of Pacific Tsunami Formation

Scientists used advanced satellite technology to observe a tsunami in real-time just 70 minutes after a massive earthquake struck off Russia's coast last year. The breakthrough observations revealed previously unseen wave patterns that could help improve tsunami prediction and coastal protection efforts.

Advanced satellite technology has provided scientists with an unprecedented look at how tsunamis form and spread across the ocean, following observations made after a powerful earthquake struck near Russia’s Kamchatka Peninsula last year.

The breakthrough research could enhance scientists’ ability to predict future tsunamis and earthquakes in subduction zones, where oceanic plates slide beneath continental plates and often generate the most devastating tsunami events.

An 8.8 magnitude earthquake occurred on July 29, 2025, creating a tsunami that traveled throughout the Pacific Ocean. Tsunamis form when massive seafloor movements during underwater earthquakes or landslides displace enormous volumes of water, creating sequences of extremely long and powerful ocean waves.

The SWOT satellite, jointly operated by NASA and the French space agency CNES, captured detailed measurements just 70 minutes after the earthquake began. Scientists observed both the primary tsunami wave and a distinctive series of smaller waves following behind it. While computer simulations had long predicted these trailing wave patterns, researchers had struggled to document them through actual observations until now.

“I believe SWOT represents a new lens for observing and studying tsunamis and their generation,” stated Ignacio Sepúlveda, a coastal engineering professor at San Diego State University who led the research published in Science journal this week.

“It is also likely to improve our understanding of the physical mechanisms that generate tsunamis, including earthquakes,” Sepúlveda continued.

Existing monitoring systems, including deep-sea pressure sensors and older satellites, have significant gaps in coverage and measurement capabilities that prevent scientists from capturing complete wave structures, particularly near oceanic trenches. The SWOT satellite surveys broad ocean areas and creates detailed two-dimensional maps showing sea surface elevation, enabling researchers to examine tsunami wave shapes, movement patterns, and spacing with unprecedented clarity.

Tsunamis rank among nature’s most powerful and devastating phenomena, sending massive waves outward from their origin point in every direction. These waves can produce catastrophic coastal flooding with deadly consequences.

While the July 2025 tsunami did not result in major casualties, other events have caused enormous loss of life, including the 2004 Indian Ocean tsunami that claimed approximately 230,000 lives.

Researchers determined that the July 2025 tsunami began within roughly 10 kilometers (six miles) of the oceanic trench where two tectonic plates meet on the seafloor. Previous monitoring methods using land-based equipment or limited seafloor sensors could not pinpoint this precise location.

The planet’s surface consists of massive plates that shift very slowly through the geological process known as plate tectonics.

Scientists discovered that when earthquake-related movement reaches close to the trench, it creates shorter waves that move more slowly and disperse over time, forming the trailing pattern behind the main tsunami wave. This phenomenon means various wave sections travel at different velocities, with longer waves moving faster and arriving first while shorter waves follow behind.

The research also demonstrated that trailing wave intensity increases when earthquake movement extends nearer to the trench, indicating these waves are connected to the location and method of tsunami formation near the trench.

“This opens a new window to understand in a better way what happens with earthquakes and tsunamis near the trench,” Sepúlveda explained regarding the SWOT observations. “In the future, this knowledge will allow us to improve models we use to evaluate tsunami hazards in coastal communities and make them more resilient.”