Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA, USA.
Science. 2013 Dec 6;342(6163):1214-7. doi: 10.1126/science.1243641.
The frictional resistance on a fault during slip controls earthquake dynamics. Friction dissipates heat during an earthquake; therefore, the fault temperature after an earthquake provides insight into the level of friction. The Japan Trench Fast Drilling Project (Integrated Ocean Drilling Program Expedition 343 and 343T) installed a borehole temperature observatory 16 months after the March 2011 moment magnitude 9.0 Tohoku-Oki earthquake across the fault where slip was ~50 meters near the trench. After 9 months of operation, the complete sensor string was recovered. A 0.31°C temperature anomaly at the plate boundary fault corresponds to 27 megajoules per square meter of dissipated energy during the earthquake. The resulting apparent friction coefficient of 0.08 is considerably smaller than static values for most rocks.
断层在滑动过程中的摩擦力控制着地震动力学。摩擦在地震过程中会产生热量；因此，地震后断层的温度可以反映摩擦力的大小。日本海沟快速钻探项目（综合大洋钻探计划 Expedition 343 和 343T）在 2011 年 3 月 9.0 级东北-关东海地震发生后 16 个月，在断层处安装了一个钻孔温度观测站，该断层的滑移约为 50 米，靠近海沟。经过 9 个月的运行，完整的传感器串被回收。板块边界断层处的 0.31°C 温度异常对应于地震期间每平方米 27 兆焦耳的耗散能量。由此得出的表观摩擦系数为 0.08，明显小于大多数岩石的静态值。
