ABSTRACT On July 29th, 2025, a large earthquake (Mw 8.8) occurred near the Kamchatka Peninsula. This event caused a tsunami that reached Japan's Pacific coast, even though the source was far away. In this study, we analyze the characteristics of earthquakes and tsunamis and discuss how they relate to the recurrence possibility and risk in Japan. We used seismic catalog data, tsunami simulation, and evacuation records to understand the impact. The recurrence of an earthquake of nearly Mw 9 within only 73 years may appear anomalous; however, our analysis indicates that it is scientifically possible. The aquaculture facilities along the eastern coast of Japan were damaged by strong currents and debris. Moreover, the tsunami arrived during the summer season when many people were at the beaches, and the heat wave made evacuation more difficult. We also consider how bathymetric features, such as Emperor Seamounts, affected tsunami behavior. Our findings show that even distant earthquakes can cause serious risk in Japan, especially when multiple hazards happen together. This study suggests that disaster planning should include compound risks and seasonal factors. This study provides important lessons for future preparedness, especially for the expected Nankai Trough earthquake and tsunami.
Laosunthara et al. (Sun,) studied this question.