SWOT Offers a Revolutionary Perspective on the Ocean

“I think of SWOT data as a new pair of glasses,” said Ruiz-Angulo. “Before, with DARTs we could only observe tsunamis at specific points across the vast ocean. Previous satellites existed, but they could at best capture a thin line of a tsunami. Now, with SWOT, we can scan swaths up to 120 kilometers wide, providing unprecedented high-resolution data of the sea surface.”

Figure 1. NASA Captures First High-Resolution Views of Pacific Tsunami.

Launched in December 2022 through a collaboration between NASA and the French space agency CNES (Centre National d’Etudes Spatiales), SWOT was designed to provide the first global assessment of Earth’s surface water. Figure 1 shows NASA Captures First High-Resolution Views of Pacific Tsunami.

This animation illustrates the simulated tsunami wave heights generated by the M8.8 Kamchatka earthquake. About 70 minutes after the quake, the path of the SWOT satellite appears. Shown in slow motion, it demonstrates how the fast-moving satellite captured both the main tsunami crest and the dispersive waves that followed.

Ruiz-Angulo and study co-author Charly de Marez noted that they had spent over two years analyzing SWOT data to study ocean processes like small eddies, never expecting to capture a tsunami.

Since large tsunamis have wavelengths longer than the ocean’s depth, they are often considered “non-dispersive,” meaning they typically travel as a single wave without breaking into leading and trailing waves.

“The SWOT data for this event challenged the idea that big tsunamis are non-dispersive,” Ruiz-Angulo explained. Numerical models accounting for dispersion matched the satellite observations of the Kamchatka tsunami more accurately.

Implications for Tsunami Forecasting

Ruiz-Angulo emphasized that this observation reveals gaps in existing tsunami models. “This ‘extra’ variability suggests the main wave could be influenced by trailing waves as it approaches certain coasts. We need to quantify this dispersive energy and assess its potential impact.”

Earlier models based on seismic and land deformation data did not fully align with DART tide gauge measurements—the predicted arrival times at two gauges differed from observations. Using an inversion analysis with DART data, the team reassessed the tsunami source.

Redefining the Earthquake Rupture

The researchers found that the Kamchatka earthquake rupture extended further south than previously thought, spanning 400 kilometers instead of the predicted 300 kilometers.

“Since the 2011 magnitude 9.0 Tohoku-oki earthquake, we’ve recognized that tsunami data provide critical constraints on shallow slip,” said co-author Diego Melgar. He noted that while including DART data in inversions is challenging due to differences in hydrodynamic versus seismic modeling, combining multiple data types is crucial for accuracy.

One of the largest Pacific tsunamis on record, triggered by a magnitude 9.0 earthquake in 1952 in the Kuril–Kamchatka subduction zone, led to the creation of the international alert system used during the 2025 event.

“With some luck, studies like ours could justify the use of satellite observations for real-time or near-real-time tsunami forecasting,” Ruiz-Angulo added.

Source: SciTECHDaily

Cite this article:

Priyadharshini S (2025), NASA Satellite Delivers First High-Resolution Images of Massive Pacific Tsunami, AnaTechMaz, pp.1234