High-velocity frictional properties of clay-rich fault gouge in a megasplay fault zone, Nankai subduction zone
High-velocity frictional properties of clay-rich fault gouge in a megasplay fault zone, Nankai subduction zone
复制标题
DOI：
10.1029/2010gl046002
复制
发表时间：
2010-12-29
影响因子：
5.2
通讯作者：
Tsutsumi, Akito
中科院分区：
文献类型：
--
作者：
Ujiie, Kohtaro;Tsutsumi, Akito
对南海俯冲带大型活动断裂带中的富粘土断层泥进行了干、湿条件下的高速摩擦实验。在干试验中，粘土矿物的脱水发生摩擦加热，和滑动弱化与热加压与水蒸发，导致在泥基质中的粘土碎屑聚集体的随机分布。在湿试验中，滑移弱化是由孔隙流体加压通过剪切增强压实和摩擦加热引起的，并且稳态剪应力对正应力的依赖性非常弱。由此产生的微观结构反映了在高剪切速率下的颗粒流体剪切流中的粒度偏析。这些结果表明，地震破裂传播容易通过粘土丰富的断层泥高速弱化，可能留下的微观结构所造成的摩擦加热或流动分选在高滑动速率。引文：Ujiie，K.，和A. Tsutsumi（2010），南海俯冲带巨型断层带中富含粘土的断层泥的高速摩擦特性，Geophys。保留信函：37，L24310，doi：10.1029/2010GL046002。
We conducted high-velocity friction experiments on clay-rich fault gouge taken from the megasplay fault zone in the Nankai subduction zone under dry and wet conditions. In the dry tests, dehydration of clay minerals occurred by frictional heating, and slip weakening is related to thermal pressurization associated with water vaporization, resulting in a random distribution of clay-clast aggregates in the gouge matrix. In the wet tests, slip weakening is caused by pore-fluid pressurization via shear-enhanced compaction and frictional heating, and there is a very weak dependence of the steady-state shear stress on the normal stress. The resulting microstructure reflects the grain size segregation in a granular-fluid shear flow at high shear rates. These results suggest that earthquake rupture propagates easily through clay-rich fault gouge by high-velocity weakening, potentially leaving the microstructures resulting from the frictional heating or the flow sorting at high slip rates. Citation: Ujiie, K., and A. Tsutsumi (2010), High-velocity frictional properties of clay-rich fault gouge in a megasplay fault zone, Nankai subduction zone, Geophys. Res. Lett., 37, L24310, doi:10.1029/2010GL046002.