On July 30, 2023, a powerful tsunami surged from the Kuril-Kamchatka Peninsula in Russia, making its way across the Pacific Ocean just 70 minutes after a significant 8.8-magnitude earthquake struck the region at 23:47 UTC. This massive seismic event is recorded as the sixth-largest earthquake globally since 1900. The resulting tsunami featured wave heights surpassing 1.5 feet, comparable to the height of a coffee table, prompting researchers to investigate the tsunami’s dynamics and geometry in detail.
A study published in GeoScienceWorld’s The Seismic Record presented findings from this incident. Researchers aimed to understand how the physical characteristics of the wave, including its rupture geometry and wave heights, influenced the tsunami’s behavior and impact. They noted that waves originating from deep waters can grow larger as they approach shallower coastal areas, revealing intricate geological phenomena.
The successful analysis of this tsunami was made possible by the Surface Water and Ocean Topography (SWOT) satellite system, developed collaboratively by NASA and a French space agency. SWOT continuously monitors Earth’s oceans from space, collecting critical data for researchers. This data was supplemented with information from deep-ocean tsunami monitoring stations known as DART buoys, which measure various tsunami-related parameters including water pressure and waveforms.
Interestingly, for this particular tsunami event, scientists anticipated non-dispersive wave behavior, where waves maintain constant shapes while traveling. However, as the tsunami progressed, its characteristics varied significantly, exhibiting changes in height, amplitude, and spacing. The waves also adapted when interacting with the complex seafloor topography, creating a diverse range of pulse patterns.
NASA’s SWOT system provided essential imagery and data to complement NOAA tsunami forecast models, showcasing the unique energy spectrum of the tsunami waves. The researchers found that even tsunamis caused by large earthquakes could yield an array of wave energies that meaningfully alter coastal conditions.
Lead author Ruiz Angulo from the University of Iceland emphasized the transformative power of the SWOT technology, likening it to receiving a new pair of glasses that bring previously unseen patterns into focus. This advancement allows for more comprehensive data collection compared to traditional DART systems, which were limited to specific monitoring points.
In conclusion, the integration of SWOT data with existing seismic records lays the groundwork for improved hazard models and a deeper understanding of how tsunami characteristics evolve from initial seismic events. This study not only enhances knowledge of past tsunami dynamics but also opens up promising avenues for future research into tsunami prediction and coastal safety.