Satellite captures the first detailed look at a giant tsunami
8 days ago
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- #earthquake
- #satellite-imaging
- A magnitude 8.8 earthquake in the Kuril-Kamchatka subduction zone on July 29, 2025, triggered a Pacific-wide tsunami and provided a rare natural experiment.
- NASA and the French space agency’s SWOT satellite captured the first high-resolution, spaceborne image of a great subduction-zone tsunami, revealing a complex, braided pattern of energy dispersion.
- Traditional tsunami forecasting assumes large waves travel as 'non-dispersive' packets, but SWOT data suggests this assumption may need revision.
- SWOT maps a 75-mile-wide swath of sea surface height, allowing scientists to observe tsunami geometry in both space and time, unlike sparse DART buoy data.
- The satellite data challenged the idea that big tsunamis behave as shallow-water waves, showing dispersive effects that could impact coastal wave behavior.
- Combining SWOT data with DART buoy records helped revise the earthquake rupture model, showing it extended farther south than initially thought.
- The study highlights the importance of integrating multiple data types (satellite, DART, seismic, geodetic) for accurate tsunami modeling and forecasting.
- High-resolution satellite altimetry can reveal the internal structure of tsunamis mid-ocean, not just their presence.
- Dispersion may shape how tsunami energy spreads into leading and trailing waves, affecting run-up timing and coastal impacts.
- The findings suggest tsunami forecasting systems need to incorporate diverse data streams to improve accuracy and real-time predictions.