[O-09] Mechanism of the 2024 Noto Peninsula Earthquake and its disaster

[O09-08] Event deposits recorded in the coastal lowlands of the Ishikawa and Toyama areas

★Invited Papers

*Atsushi Urabe¹, Yasuhiro Takashimizu¹, Koji Suzuki¹, Kyoko Kataoka¹, Kenji Nishina², Kazuomi Hirakawa³, Hideo Sakai⁴ (1.Research Institute for Natural Hazards and Disaster Recovery, Niigata University, 2.Research Institute of Energy, Environment and Geology, Hokkaido Research Organization, 3.Professor Emeritus, Hokkaido University, 4.Visiting Professor, University of Toyama)

Keywords:Tsunami deposit, Coastal lowlands, Ishikawa and Toyama areas

The Japan Sea Earthquake and Tsunami Research Project conducted a tsunami sediment survey from the northern Noto Peninsula to the Toyama Bay coastal area in 2014. In this study, outcrops near the coast (sediments on low terraces) and borehole investigations in the coastal lowlands and old lagoons were conducted. As a result, several event deposits were identified as likely to be of tsunami origin. In the coastal outcrop survey, event deposits were identified at Wanzaki, Suzu City, and Akazaki, Noto Town, indicating the 10th-11th and 9th-10th centuries, and 1800-2000 years ago. Borehole investigations were also conducted in the Suzu area, the Junicho lagoons in Himi, the Housouzu Lagoon in Imizu, the Ashiarai Lagoon in Imizu, and the Ikuji in Kurobe. As a result, the event deposits common to all sites along the Toyama Bay coast, including the Suzu area, were identified as (1) approximately 7,900-7,800 years ago, (2) approximately 5,000-4,800 years ago, (3) approximately 2,500-2,000 years ago, and (4) approximately 800-700 years ago. These results in 2014 show the tsunami history in the area around the Noto Peninsula. Here, we reexamine the history and sources of these tsunami events in light of the tsunami caused by the 2024 Noto Peninsula earthquake.