Seismic slip propagation to the updip end of plate boundary subduction interface faults: Vitrinite reflectance geothermometry on Integrated Ocean Drilling Program NanTro SEIZE cores
Seismic slip propagation to the updip end of plate boundary subduction interface faults: Vitrinite reflectance geothermometry on Integrated Ocean Drilling Program NanTro SEIZE cores
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DOI：
10.1130/g31642.1
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发表时间：
2011-04
期刊：
影响因子：
5.8
通讯作者：
A. Sakaguchi;F. Chester;D. Curewitz;O. Fabbri;D. Goldsby;G. Kimura;Chun‐Feng Li;Y. Masaki;E. Screaton;A. Tsutsumi;K. Ujiie;A. Yamaguchi
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文献类型：
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作者：
A. Sakaguchi;F. Chester;D. Curewitz;O. Fabbri;D. Goldsby;G. Kimura;Chun‐Feng Li;Y. Masaki;E. Screaton;A. Tsutsumi;K. Ujiie;A. Yamaguchi
沿俯冲型板块边界的地震断层在海啸成因中起着基础性作用。在综合大洋钻探计划(IODP)南开海槽孕震带实验(NanTro Capture)第一阶段，板块边界俯冲断层的上倾端在南开海槽(日本近海)钻探和取心，那里曾多次发生大地震和海啸，包括公元1944年的托南凯(Mw=8.1)地震。样品来自连接深部板块边界和沉积楔体脚趾处海底的前缘逆冲，以及从板块边界滑脱分支出来的巨型断层。吸积楔体的脚趾传统上被认为是无地震的，但镜质组反射地质测温显示，所研究的两个断裂带经历了380℃以上的局部温度，这表明沿这两个断裂带发生了摩擦加热，并暗示同震滑动至少传播了一次到巨型断裂的上倾端和增积楔体的脚趾。
Seismic faulting along subduction-type plate boundaries plays a fundamental role in tsunami genesis. During the Integrated Ocean Drilling Program (IODP) Nankai Trough Seismogenic Zone Experiment (NanTro SEIZE) Stage 1, the updip ends of plate boundary subduction faults were drilled and cored in the Nankai Trough (offshore Japan), where repeated large earthquakes and tsunamis have occurred, including the A.D. 1944 Tonankai (Mw = 8.1) earthquake. Samples were obtained from the frontal thrust, which connects the deep plate boundary to the seafloor at the toe of the accretionary wedge, and from a megasplay fault that branches from the plate boundary decollement. The toe of the accretionary wedge has classically been considered aseismic, but vitrinite reflectance geothermometry reveals that the two examined fault zones underwent localized temperatures of more than 380 °C. This suggests that frictional heating occurred along these two fault zones, and implies that coseismic slip must have propagated at least one time to the updip end of the megasplay fault and to the toe of the accretionary wedge.