Effects of the Tsunami Generated by the 1662 Hyuga-Nada Earthquake off Miyazaki Prefecture, Japan
Effects of the Tsunami Generated by the 1662 Hyuga-Nada Earthquake off Miyazaki Prefecture, Japan
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DOI：
10.1007/s00024-022-03198-3
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发表时间：
2022-12-15
影响因子：
2
通讯作者：
Kase, Yoshihiro
中科院分区：
文献类型：
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作者：
Ioki, Kei;Yamashita, Yusuke;Kase, Yoshihiro
日向滩地区位于太平洋南海海槽西南部，由于菲律宾海板块俯冲，该地区多次发生M7级板间地震。日向滩地区历史上有记录的最大地震是1662年发生在日本九州东南部宫崎县附近的日向滩地震，引发了海啸。该地区也是板块边界浅部慢地震活跃区。 2011年东北地震证实浅源慢震活动区也成为海啸震源区。我们假设1662年异常大的海啸是由浅层慢地震活动源区的同震滑动引起的。我们根据最近的地球物理观测构建了 1662 年日向滩地震的断层模型。使用基于假设构建的断层模型对海啸进行了数值模拟。根据断层模型估计总地震矩为 9.8 x 10(20) Nm (M-w 7.9)。估计的断层模型可以解释本研究中认识到的、其他研究报告过的可能海啸事件沉积物的分布以及历史记录中的海啸高度。基于地球物理发现的假设已被发现是正确的。
The Hyuga-nada region is located in the southwestern part of the Nankai Trough in the Pacific Ocean, where M7 class interplate earthquakes have been repeatedly occurring because of the subduction of the Philippine Sea Plate. The largest earthquake recorded in history for the Hyuga-nada region was the Hyuga-nada earthquake of 1662, which occurred off Miyazaki Prefecture in the southeastern area of Kyushu region, Japan, generating a tsunami. The region is also an area where slow earthquakes are active at the shallow part of the plate boundary. It is confirmed by the 2011 Tohoku earthquake that the active area of shallow slow earthquakes also became a tsunami source area. We hypothesize that the unusually large tsunami of 1662 was caused by the coseismic slipping of the active source area of shallow slow earthquakes. We constructed the fault model of the 1662 Hyuga-nada earthquake based on recent geophysical observations. A numerical simulation of the tsunami was carried out using the fault model constructed based on hypotheses. The total seismic moment was 9.8 x 10(20) Nm (M-w 7.9) estimated from the fault model. The estimated fault model can explain the distribution of the likely tsunami event deposits which were recognized in this study and also have been reported by other studies and tsunami heights in historical records. Hypotheses based on geophysical findings have been found to be correct.