Stratigraphic Control of Frontal Décollement Level and Structural Vergence and Implications for Tsunamigenic Earthquake Hazard in Sumatra, Indonesia
Stratigraphic Control of Frontal Décollement Level and Structural Vergence and Implications for Tsunamigenic Earthquake Hazard in Sumatra, Indonesia
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印度尼西亚苏门答腊岛锋面滑脱水平和构造辐散的地层控制及其对海啸地震灾害的影响
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发表时间：
2019
影响因子：
3.5
通讯作者：
Satish C. Singh
中科院分区：
文献类型：
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作者：
K. Bradley;Yanfang Qin;H. Carton;N. Hananto;F. Villanueva;F. Leclerc;S. Wei;P. Tapponier;K. Sieh;Satish C. Singh
断层破裂向海底的传播可能是大逆冲断层地震期间海啸产生增强的原因。2010年10月25日，在明打威海啸地震破裂的北方边界收集的新的高分辨率地震反射剖面和条带水深测量显示，巽他巨型逆冲断层前缘的地层水平及其前缘斜坡断层的聚散度存在显著和系统的横向变化。在斜坡断层均匀向海倾的地方，滑脱层位于一个强反射层的顶部，标志着推断的远洋沉积物顶部。当斜坡断层是两向的（既向陆地又向海洋）时，滑脱层位于俯冲碎屑序列内，位于推断为远源扇泥的地震透明单元上方。在斜坡断层均匀地向陆地倾伏的地方，滑脱层直接位于俯冲的研究者断裂带的洋壳顶部。2010年海啸地震期间增强的表面隆起和海啸发生似乎与破裂传播到具有发育良好的结构分叉的前沿区域相一致。前缘分叉是滑动累积期间低基底牵引力的地质信号，在苏门答腊近海，这种结构样式可能标志着由小型浅层巨型逆冲断层破裂造成的海啸危险增强的区域，这些断层在海沟附近传播到传入的陆源层序中。
Propagation of fault rupture to the seafloor is a likely cause of enhanced tsunami generation during megathrust earthquakes. New, high‐resolution seismic reflection profiles and swath bathymetry collected across the northern limit of the Mw 7.8, 25 October 2010 Mentawai tsunami earthquake rupture reveal significant and systematic lateral variations in both the stratigraphic level of the frontal Sunda megathrust and the vergence of its frontal ramp faults. Where ramp faults are uniformly seaward vergent, the décollement resides on top of a strong reflector marking the inferred top of pelagic sediments. Where ramp faults are bivergent (both landward and seaward), the décollement is localized within the subducting clastic sequence, above a xseismically transparent unit inferred to be distal fan muds. Where ramp faults are uniformly landward vergent, the décollement is directly on top of the oceanic crust of the subducting Investigator Fracture Zone. Enhanced surface uplift and tsunamigenesis during the 2010 tsunamigenic earthquake appear to have coincided with propagation of rupture into frontal areas with well‐developed structural bivergence. Frontal bivergence is a geological signal of low basal traction during accrual of slip, and offshore of Sumatra this structural style may mark areas of enhanced tsunami hazard posed by small‐magnitude, shallow megathrust ruptures that propagate into the incoming terrigenous sequence at near‐trench levels.
2004 年苏门答腊地震的上倾破裂被厚厚的硬质沉积物扩展
影响因子：
18.3
作者：
Gulick S
通讯作者：
Gulick S
影响因子：
56.9
作者：
Huepers, Andre;Torres, Marta E.;Zhao, Xixi
通讯作者：
Zhao, Xixi