Slip distribution of the 1952 Tokachi‐Oki earthquake (M 8.1) along the Kuril Trench deduced from tsunami waveform inversion
Slip distribution of the 1952 Tokachi‐Oki earthquake (M 8.1) along the Kuril Trench deduced from tsunami waveform inversion
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根据海啸波形反演推导出 1952 年十胜冲地震（M 8.1）沿千岛海沟的滑动分布
DOI：
10.1029/2002jb001976
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发表时间：
2003
影响因子：
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通讯作者：
S. Yamaki
中科院分区：
文献类型：
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作者：
K. Hirata;E. Geist;K. Satake;Y. Tanioka;S. Yamaki
我们对日本记录的13个海啸波形进行了反演，以估计1952年发生在北海道东南沿南千岛岛俯冲带的Tokachi-Oki地震（8.1级）的滑动分布。先前根据海啸传播时间估算的震源面积[Hatori， 1973]与观测到的余震分布不一致。结果表明，在波取海啸震源以东的余震区发生了大量的滑动，表明海沟附近的部分板块间逆冲被主震破裂。我们还发现，在发震界面的较深处，就在波取海啸震源区域的中心下方，有超过5米的滑动。该地区在主震期间应力下降幅度最大，几乎没有余震。与以往的均匀滑动断层模型相比，非均匀滑动模型能更好地解释北海道东部海岸的大海啸高度。总地震矩估计为1.87 × 1021 N m，给出的矩震级为Mw = 8.1。修订后的海啸震源面积估计为25.2 × 103 km2，比以前的海啸震源面积大约3倍。在1952年地震破裂区及其周围发生的4次M ~ 7级大地震中，有3次发生在滑动量相对较小的地区边缘。我们还发现，靠近破裂区边缘的俯冲海山可能阻碍了沿板块界面的滑动。
[1] We inverted 13 tsunami waveforms recorded in Japan to estimate the slip distribution of the 1952 Tokachi-Oki earthquake (M 8.1), which occurred southeast off Hokkaido along the southern Kuril subduction zone. The previously estimated source area determined from tsunami travel times [Hatori, 1973] did not coincide with the observed aftershock distribution. Our results show that a large amount of slip occurred in the aftershock area east of Hatori's tsunami source area, suggesting that a portion of the interplate thrust near the trench was ruptured by the main shock. We also found more than 5 m of slip along the deeper part of the seismogenic interface, just below the central part of Hatori's tsunami source area. This region, which also has the largest stress drop during the main shock, had few aftershocks. Large tsunami heights on the eastern Hokkaido coast are better explained by the heterogeneous slip model than previous uniform-slip fault models. The total seismic moment is estimated to be 1.87 × 1021 N m, giving a moment magnitude of Mw = 8.1. The revised tsunami source area is estimated to be 25.2 × 103 km2, ∼3 times larger than the previous tsunami source area. Out of four large earthquakes with M ∼ 7 that subsequently occurred in and around the rupture area of the 1952 event, three were at the edges of regions with relatively small amount of slip. We also found that a subducted seamount near the edge of the rupture area possibly impeded slip along the plate interface.
DOI：
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发表时间：
1975-10
期刊：
--
影响因子：
--
作者：
H. Kanamori;D. L. Anderson
通讯作者：
H. Kanamori;D. L. Anderson