Rupture Directivity Analysis of the 2018 Hokkaido Eastern Iburi Earthquake and Its Seismotectonic Implication
Rupture Directivity Analysis of the 2018 Hokkaido Eastern Iburi Earthquake and Its Seismotectonic Implication
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2018年北海道胆振东部地震破裂方向性分析及其地震构造意义
DOI：
10.1785/0220190131
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发表时间：
2019-11
影响因子：
3.3
通讯作者：
Zhichao Shen
中科院分区：
文献类型：
--
作者：
Chong Zang;Sidao Ni;Zhichao Shen
2018年9月5日发生在北海道岛南部的北海道东伊布里6.6级地震是一次灾难性的特殊事件。与通常的地壳浅源地震不同，这次地震发生在震源深度约37公里处，靠近莫霍面。为了推断2018年北海道地震的破裂特征，我们通过反演地震波形来确定震源机制和震源深度。结果表明，这次逆冲型地震的震源深度（26 km左右）比震源深度浅，表明该次逆冲型地震是在下地壳内向上破裂传播和主导破裂的。我们还研究了基于波形模拟的成因断层和破裂方向性。倾向于南北走向的陡倾断层（70）为发矿断层。根据余震分布和破裂方向性，估计破裂总长度约为30公里。我们认为，在俯冲带界面上方的下地壳中具有低温和复杂应力场的孕震模型可以解释这一事件。
The M w 6.6 Hokkaido Eastern Iburi earthquake striking southern Hokkaido Island on 5 September 2018 was a disastrous and peculiar event. In contrast to the usually shallow crustal earthquakes, this event occurred at a hypocentral depth about 37 km, close to the Moho discontinuity. To infer the rupture feature of the 2018 Hokkaido earthquake, we determine focal mechanism and centroid depth of the event with inversion of teleseismic waveforms. The result reveals that the centroid (at depth about 26 km) of this thrust earthquake is shallower than the hypocenter, which suggests the upward rupture propagation and dominant rupture in the lower crust. We also investigate the causative fault and rupture directivity based on waveform modeling. The steeply dipping fault (70) with strike in the north–south direction is preferred to be the causative fault. The total dimension of rupture is estimated to be about 30 km, based on the aftershock distribution and rupture directivity. We propose that a seismogenic model with low temperature and complex stress field in the lower crust above the subduction‐zone interface may explain this event.
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影响因子：
5.2
作者：
Z. Ross;H. Kanamori;E. Hauksson
通讯作者：
Z. Ross;H. Kanamori;E. Hauksson
DOI：
10.1186/bf03353340
发表时间：
2004-12
期刊：
Earth, Planets and Space
影响因子：
--
作者：
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通讯作者：
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影响因子：
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作者：
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影响因子：
5.3
作者：
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通讯作者：
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影响因子：
3
作者：
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通讯作者：
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