Detailed coseismic slip distribution of the 1944 Tonankai Earthquake estimated from tsunami waveforms
Detailed coseismic slip distribution of the 1944 Tonankai Earthquake estimated from tsunami waveforms
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根据海啸波形估算的 1944 年东南海地震的详细同震滑移分布
DOI：
10.1029/2000gl012284
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发表时间：
2001
影响因子：
5.2
通讯作者：
K. Satake
中科院分区：
文献类型：
--
作者：
Y. Tanioka;K. Satake
根据海啸波形反演结果，估算了1944年东南海地震断层面上的同震滑动分布。从以前的研究[佐竹，1993]进行了三项改进。这些是：（1）较小的子断层用于解析详细的滑动分布;（2）子断层更好地拟合板块界面几何形状;（3）使用更精细和更准确的测深数据。反演结果表明，在志摩半岛外的板块界面上发生了约3 m的最大滑动。总地震矩估计为2.0 × 1021 Nm（Mw 8.2）。结果证实了1944年东南海地震并没有使东海地区下面的板块界面破裂，支持了Ishibashi [1981]提出的东海地区存在地震空区的观点。虽然菊池等人[1999]没有根据强震数据估计地震矩释放，但在大滑动区东北部的厚见半岛下方的板块界面上约1.5 m的滑动对于解释观测到的海啸波形是必要的。这可能表明，厚见半岛下方的破裂是缓慢的。
Coseismic slip distribution on the fault plane of the 1944 Tonankai earthquake is estimated from inversion of tsunami waveforms. Three improvements from a previous study [Satake, 1993] are made. These are: (1) smaller subfaults are used to resolve detailed slip distribution; (2) the sub faults fit better to the plate interface geometry; and (3) finer and more accurate bathymetry data is used. The inversion result shows that a maximum slip of about 3 m occurred on the plate interface off Shima peninsula. The total seismic moment is estimated to be 2.0 × 1021 Nm (Mw 8.2). The result confirms that the 1944 Tonankai earthquake did not rupture the plate interface beneath the Tokai region and supports the existence of the seismic gap in the Tokai region suggested by Ishibashi [1981]. The slip of about 1.5 m on the plate interface beneath Atsumi peninsula, northeast of the large slip area, is necessary to explain the observed tsunami waveforms, although no seismic moment release was estimated from strong motion data by Kikuchi et al. [1999]. This may suggest that the rupture beneath Atsumi peninsula was slow.