Links between clay transformation and earthquakes along the Costa Rican subduction margin
Links between clay transformation and earthquakes along the Costa Rican subduction margin
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哥斯达黎加俯冲边缘粘土转变与地震之间的联系
DOI：
10.1002/2017gl073744
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发表时间：
2017
影响因子：
5.2
通讯作者：
R. Harris
中科院分区：
文献类型：
--
作者：
R. Lauer;D. Saffer;R. Harris
我们调查了蒙皂石粘土转化的深度分布及其沿着走向的变化在中美洲海沟近海哥斯达黎加。我们利用最新的良好约束的热模型，完善我们的边缘的热结构的理解，并捕捉显着的沿着走向的变化。使用这些热模型，连同沉积物成分定义的钻井，我们计算的蒙皂石转化和相关的流体生产的分布。我们发现，大型（M > 6.9）位置良好的巨型逆冲断层地震的震源始终位于峰值流体生产的下倾。我们认为，与蒙皂石转化相关的二氧化硅胶结作用促进了岩化作用和滑移弱化行为，与流体压力下降相结合，促进了不稳定滑移的开始。地震破裂向上延伸到峰值反应区域，可能是由于超孔隙压力促进其传播。这些结果与蒙皂石转变有助于粘滑行为的发生并作为地震成核和传播的重要控制的假设一致。
We investigate the depth distribution of smectite clay transformation and its along‐strike variability at the Middle America Trench offshore Costa Rica. We take advantage of recent well‐constrained thermal models that refine our understanding of the margin's thermal structure and which capture significant along‐strike variability. Using these thermal models, together with sediment compositions defined by drilling, we compute the distribution of smectite transformation and associated fluid production. We show that the hypocenters of large (M > 6.9) well‐located megathrust earthquakes lie consistently downdip of peak fluid production. We suggest that silica cementation associated with smectite transformation promotes lithification and slip‐weakening behavior that, in combination with declining fluid pressures, facilitate the initiation of unstable slip. The earthquake ruptures extend updip into the region of peak reaction, possibly due to excess pore pressures that facilitate their propagation. These results are consistent with the hypothesis that smectite transformation contributes to the onset of stick‐slip behavior and acts as an important control on earthquake nucleation and propagation.
影响因子：
3.7
作者：
C. Ranero;I. Grevemeyer;H. Sahling;U. Barckhausen;C. Hensen;K. Wallmann;W. Weinrebe;P. Vannucchi;R. Huene;K. Mcintosh
通讯作者：
C. Ranero;I. Grevemeyer;H. Sahling;U. Barckhausen;C. Hensen;K. Wallmann;W. Weinrebe;P. Vannucchi;R. Huene;K. Mcintosh
影响因子：
56.9
作者：
Huepers, Andre;Torres, Marta E.;Zhao, Xixi
通讯作者：
Zhao, Xixi
影响因子：
2.3
作者：
Arroyo, Ivonne G.;Husen, Stephan;Flueh, Ernst R.
通讯作者：
Flueh, Ernst R.