Rupture Process During the Mw 8.1 2017 Chiapas Mexico Earthquake: Shallow Intraplate Normal Faulting by Slab Bending
Rupture Process During the Mw 8.1 2017 Chiapas Mexico Earthquake: Shallow Intraplate Normal Faulting by Slab Bending
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DOI：
10.1002/2017gl075956
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发表时间：
2017-12
影响因子：
5.2
通讯作者：
R. Okuwaki;Y. Yagi
中科院分区：
文献类型：
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作者：
R. Okuwaki;Y. Yagi
利用全球观测到的远震波形，通过运动学波形反演构建了2017年墨西哥恰帕斯8.1级地震的震源模型，结果表明该地震是在一个陡倾平面上的正断层事件，主要滑动集中在相对较浅的28千米深度附近。模拟的破裂演化显示，破裂从震源向西北方向单侧向下倾方向传播，主破裂的下倾宽度被限制在板块界面以下不到30千米，这表明板块弯曲引起的下倾张应力是此次地震的主要原因。破裂前沿在主破裂的西北端（与俯冲的特万特佩克断裂带相交处）突然减速，这表明该断裂带可能抑制了进一步的破裂传播。
A seismic source model for the Mw 8.1 2017 Chiapas, Mexico, earthquake was constructed by kinematic waveform inversion using globally observed teleseismic waveforms, suggesting that the earthquake was a normal‐faulting event on a steeply dipping plane, with the major slip concentrated around a relatively shallow depth of 28 km. The modeled rupture evolution showed unilateral, downdip propagation northwestward from the hypocenter, and the downdip width of the main rupture was restricted to less than 30 km below the slab interface, suggesting that the downdip extensional stresses due to the slab bending were the primary cause of the earthquake. The rupture front abruptly decelerated at the northwestern end of the main rupture where it intersected the subducting Tehuantepec Fracture Zone, suggesting that the fracture zone may have inhibited further rupture propagation.