Abundant aftershock sequence of the 2015 Mw7.5 Hindu Kush intermediate-depth earthquake
Abundant aftershock sequence of the 2015 Mw7.5 Hindu Kush intermediate-depth earthquake
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DOI：
10.1093/gji/ggy016
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发表时间：
2018-05
影响因子：
2.8
通讯作者：
Chenyu Li;Zhigang Peng;D. Yao;Hao Guo;Z. Zhan;Haijiang Zhang
中科院分区：
文献类型：
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作者：
Chenyu Li;Zhigang Peng;D. Yao;Hao Guo;Z. Zhan;Haijiang Zhang
2015年兴都库什7.5级地震发生在阿富汗兴都库什地区地下213公里处。虽然全球地震目录中没有许多早期余震，但500公里内的8个宽带台连续记录了这一序列。在这里，我们使用波形匹配技术来系统地检测主震周围的地震。在主震后35天内检测到3000多次地震，相比之下，国家高级地震系统目录中有42次(国际地震中心目录中有196次)。余震序列一般遵循大森定律，衰减常数p=0.92。我们还应用了最近开发的双对双差技术来重新定位所有检测到的余震。它们大多位于主震震中以西，与主震破裂向西传播一致。余震勾勒出一个近乎垂直的向南倾斜的平面，与主震的一个节面很好地匹配。我们得出的结论是，这次中深震的余震序列与浅源地震的余震序列有许多相似之处，并推测浅源地震和中深源地震有一些共同的机制。
The 2015 M_w7.5 Hindu Kush earthquake occurred at a depth of 213 km beneath the Hindu Kush region of Afghanistan. While many early aftershocks were missing from the global earthquake catalogues, this sequence was recorded continuously by eight broad-band stations within 500 km. Here we use a waveform matching technique to systematically detect earthquakes around the main shock. More than 3000 events are detected within 35 d after the main shock, as compared with 42 listed in the Advanced National Seismic System catalogue (or 196 in the International Seismological Centre catalogue). The aftershock sequence generally follows the Omori's law with a decay constant p = 0.92. We also apply the recently developed double-pair double-difference technique to relocate all detected aftershocks. Most of them are located to the west of the hypocentre of the main shock, consistent with the westward propagation of the main-shock rupture. The aftershocks outline a nearly vertical southward dipping plane, which matches well with one of the nodal planes of the main shock. We conclude that the aftershock sequence of this intermediate-depth earthquake shares many similarities with those for shallow earthquakes and infer that there are some common mechanisms responsible for shallow and intermediate-depth earthquakes.