New insights into ocean wave propagation patterns, discovered by an international team of scientists including Russian specialists, promise a significant enhancement of early tsunami warning systems along Russia`s Pacific coast (specifically, the Sea of Japan shoreline). This breakthrough is expected to substantially reduce potential damage from devastating natural disasters.
Tsunamis are widely recognized as one of the most perilous natural phenomena, capable of inflicting immense economic damage and jeopardizing the lives and well-being of hundreds of thousands of people.
Research teams from the Shirshov Institute of Oceanology of the Russian Academy of Sciences (Moscow), the Institute of Marine Geology and Geophysics of the Far Eastern Branch of the Russian Academy of Sciences (Yuzhno-Sakhalinsk), and the University of Bath (UK) conducted extensive studies focusing on the 2024 tsunami in the Sea of Japan.
Initially, the researchers examined the characteristics of tsunami wave propagation in the northern part of the Sea of Japan. This analysis utilized data collected from Russian and Japanese coastal stations, as well as readings from seafloor pressure sensors.
It was observed that wave height varied considerably depending on the local topography. While in the open sea, wave heights did not exceed 15 centimeters, they reached up to 65 centimeters in the port of Kholmsk on Sakhalin Island due to amplification effects, specifically resonance. This phenomenon is attributed to the unique V-shaped configuration of the Tatar Strait, which intensifies long waves, along with specific amplification conditions within certain bays.
Subsequently, scientists employed numerical modeling to simulate the generation and propagation of tsunami waves following the January 2024 earthquake, concentrating on the southern and central regions of the Sea of Japan. This work revealed that the Yamato Seamount acts as a natural barrier, significantly reducing wave heights along the coast of Primorye.
In the latest phase of their research, the scientific group investigated sea level fluctuations caused by Typhoons Maysak and Haishen in 2020. The analysis was based on data from sea level measurement stations along the western coast of the Sea of Japan, the southern coast of the Korean Peninsula, and the Korean island of Ulleungdo. The results clearly demonstrated that the characteristics of typhoon-generated waves and tsunami waves differ significantly: typhoons produce broadband waves with short periods (less than 10 minutes), whereas tsunamis are characterized by dome-shaped waves with periods ranging from 6 to 40 minutes.
“The information obtained provides a deeper understanding of how geographical features – such as coastal and seafloor relief – influence the propagation and intensity of waves generated by earthquakes in the sea. This knowledge will help us more accurately identify settlements on the Russian coast of the Sea of Japan most vulnerable to tsunami threats,” commented Igor Medvedev, Head of the S.L. Solovyov Tsunami Laboratory at the Shirshov Institute of Oceanology of the Russian Academy of Sciences.
Looking ahead, the scientists plan to conduct detailed tsunami risk zoning for the Russian coast of the Sea of Japan. This will enable them to estimate maximum wave heights for various recurrence periods. These forthcoming data will be a crucial element in refining operational forecasts for potential natural disasters along the coast.
The findings of these significant studies, supported by a grant from the Russian Science Foundation (RSF), were published in the journal Ocean Engineering.
