The 2017 Mw 8.2 Chiapas, Mexico, Earthquake: Energetic Slab Detachment
The 2017 Mw 8.2 Chiapas, Mexico, Earthquake: Energetic Slab Detachment
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DOI：
10.1002/2017gl076085
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发表时间：
2017-12
影响因子：
5.2
通讯作者：
L. Ye;T. Lay;Yefei Bai;K. Cheung;H. Kanamori
中科院分区：
文献类型：
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作者：
L. Ye;T. Lay;Yefei Bai;K. Cheung;H. Kanamori
2017年9月8日，一次大的(Mw 8.2)正断层地震在俯冲科科斯板块内破裂，距离特万特佩克缺口下的中美洲海沟向陆地方向约70公里。对远震和海啸资料的迭代反演、模拟和GPS位移预测表明，急倾斜破裂沿瓦哈卡海岸走向向西北延伸约180公里，深度约30~70公里，最大滑移量约13m。断裂可能是对下倾板块拉动的响应，穿过年轻俯冲板块的整个岩石圈。海沟与大断裂交汇处的板块边界区域表现为摩擦耦合，影响滑脱的位置。宽带体波震级(MB)和矩尺度辐射能量(ER/M0)的比较表明，实验室内地震往往比板间地震更具能量，这是2017年观测到的强烈地面震动的原因。
On 8 September 2017, a great (Mw 8.2) normal faulting earthquake ruptured within the subducting Cocos Plate ~70 km landward from the Middle American Trench beneath the Tehuantepec gap. Iterative inversion and modeling of teleseismic and tsunami data and prediction of GPS displacements indicate that the steeply dipping rupture extended ~180 km to the northwest along strike toward the Oaxaca coast and from ~30 to 70 km in depth, with peak slip of ~13 m. The rupture likely broke through the entire lithosphere of the young subducted slab in response to downdip slab pull. The plate boundary region between the trench and the fault intersection with the megathrust appears to be frictionally coupled, influencing location of the detachment. Comparisons of the broadband body wave magnitude (mB) and moment‐scaled radiated energy (ER/M0) establish that intraslab earthquakes tend to be more energetic than interplate events, accounting for strong ground shaking observed for the 2017 event.