Estimation of temperature rise in a shallow slip zone of the megasplay fault in the Nankai Trough
Estimation of temperature rise in a shallow slip zone of the megasplay fault in the Nankai Trough
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DOI：
10.1016/j.tecto.2009.08.001
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发表时间：
2009-12
期刊：
影响因子：
2.9
通讯作者：
T. Hirono;K. Ujiie;T. Ishikawa;T. Mishima;Y. Hamada;M. Tanimizu;W. Soh;M. Kinoshita
中科院分区：
文献类型：
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作者：
T. Hirono;K. Ujiie;T. Ishikawa;T. Mishima;Y. Hamada;M. Tanimizu;W. Soh;M. Kinoshita
从南海海槽的俯冲边界巨型逆冲断层分支出来的巨型活动断层被认为引起了与过去托南凯地震有关的大海啸。由于断层中记录的温度可以限制地震滑动的参数，我们评估了几个温度代理（流体流动微量元素浓度，锶同位素，磁性矿物，无机碳含量，和拉曼光谱的碳质材料）从一个本地化的滑动带，在现场C0004综合大洋钻探计划远征316采样。我们的研究结果表明，巨型断层的浅层部分没有经历过300 °C以上的温度。我们还发现，除了剪切应力和滑移距离，滑移率和孔隙率是摩擦热的有效参数，结合热扩散的数值分析表明。通过这些代理估计的滑动速率可能表明，断层没有在海底附近高速滑动。
A megasplay fault branching from the subduction boundary megathrust in the Nankai Trough is thought to have caused large tsunamis associated with past Tonankai earthquakes. Because the temperature recorded in the fault can constrain parameters of seismic slip, we evaluated several temperature proxies (fluid-mobile trace element concentrations, Sr isotopes, magnetic minerals, inorganic carbon content, and Raman spectra of carbonaceous material) in material from a localized slip zone, sampled at Site C0004 by Integrated Ocean Drilling Program Expedition 316. Our results showed that the shallow part of the megasplay fault has not experienced temperatures above 300 °C. We also found that in addition to shear stress and slip distance, slip rate and porosity are effective parameters for frictional heat, as demonstrated by numerical analysis incorporating thermal diffusion. The slip rate estimated through these proxies may indicate that the fault did not slip with high velocity near the seafloor.