Tsunami heights on the Korean east coast from submarine active faults along the eastern margin of the Sea of Japan

Large earthquakes along the eastern margin of the Sea of Japan, such as the 1983 Central Japan Sea Earthquake (M 7.7) or the 1993 Southwest Off Hokkaido Earthquake (M 7.8) generated tsunamis that reached and caused damage on the east coast of Korea, whereas tsunamis from the recent 2024 Noto Peninsula Earthquake (M 7.6) were much smaller. In this study, we computed tsunamis on the Korean east coast from 60 fault models proposed by a Japanese committee in 2014 (MLIT model). The maximum tsunami height at many locations is produced by the F24 fault (Mw 7.9, corresponding to the 1983 earthquake) and the F17 fault (Mw 7.8, a model of the 1993 earthquake). In addition, the F20 (Mw 7.8), F28 (Mw 7.7), and F30 (Mw 7.8) faults, located off Aomori, Akita, and Yamagata Prefectures, also produce large tsunamis on the Korean coast, because of their fault strike and propagation effects through Yamato Rise. The tsunami heights from fault models of the 1940 Off Shakotan Peninsula Earthquake (F07), the 1964 Niigata Earthquake (F34), and the 2024 Noto Peninsula Earthquake (F43) are smaller, as they are located further to the north or on the continental shelf with shallower water depth.

日本海东部边缘的大型地震，例如1983年日本海中部地震（震级M 7.7）与1993年北海道西南近海地震（震级M 7.8），其所引发的海啸曾抵达韩国东海岸并造成破坏；而2024年能登半岛地震（M 7.6）引发的海啸规模则显著更小。本研究针对日本国土交通省（MLIT）2014年提出的60种断层模型，模拟计算了其在韩国东海岸引发的海啸响应。在多数测点处，最大海啸波高由F24断层（矩震级Mw 7.9，对应1983年日本海中部地震）与F17断层（矩震级Mw 7.8，为1993年北海道西南近海地震的模拟模型）所主导。此外，分布于青森县、秋田县与山形县近海的F20（矩震级Mw 7.8）、F28（矩震级Mw 7.7）以及F30（矩震级Mw 7.8）断层，同样会在韩国海岸引发大规模海啸，这源于其断层走向特征以及海啸经大和隆起（Yamato Rise）传播的动力学效应。而对应1940年积丹半岛近海地震的断层模型（F07）、1964年新潟地震的断层模型（F34）以及2024年能登半岛地震的断层模型（F43），其所引发的海啸波高均相对更小，原因在于这些断层的位置更偏北，或是坐落于水深较浅的大陆架区域。