Flash Heating and Local Fluid Pressurization Lead to Rapid Weakening in Water-Saturated Fault Gouges
Flash Heating and Local Fluid Pressurization Lead to Rapid Weakening in Water-Saturated Fault Gouges
复制标题
闪速加热和局部流体加压导致水饱和断层泥快速弱化
DOI：
10.1029/2018jb016132
复制
发表时间：
2018-10-01
影响因子：
3.9
通讯作者：
He, Honglin
中科院分区：
文献类型：
--
作者：
Yao, Lu;Ma, Shengli;He, Honglin
在某些地震中，浅层同震断层位移相当大，这意味着断层泥和沉积物在地震滑动过程中具有极低的动摩擦力。然而，在潮湿条件下的断层泥的动态弱化机制仍然没有得到很好的约束。在这里，我们提出了直接的证据发生的闪速加热和局部流体加压在水饱和的泥，通过执行低到高的速度（V=10 μ m/s至1米/秒）的摩擦实验在压力容器中，在专门设计的条件下，以抑制削弱的影响，散装热和摩擦引起的加压。随着滑移率的增加，断层泥的速度从强化向急剧的弱化转变。当V >= 0.04 m/s时，滑动开始时开始出现强动力弱化（
Coseismic fault displacement is quite large at shallow depths in some earthquakes, and it implies that fault gouges and sediments have extremely low dynamic friction during seismic slip. However, the dynamic weakening mechanisms of gouges under wet conditions are still not well constrained. Here we present direct evidence for the occurrence of flash heating and local fluid pressurization in water-saturated gouges, by performing low- to high-velocity (V=10 mu m/s to 1 m/s) friction experiments in a pressure vessel, under conditions specially designed to suppress weakening effects of bulk thermal and compaction-induced pressurization. The tested gouges exhibit transition from velocity strengthening to drastic velocity weakening as slip rates increase. Strong dynamic weakening starts to occur at V >= 0.04 m/s at the initiation of sliding (