论文标题
大型侵蚀事件和瞬态正常应力变化对断层的地震性的影响
The Impact of Large Erosional Events and Transient Normal Stress Changes on the Seismicity of Faults
论文作者
论文摘要
陡峭景观的长期侵蚀被戏剧性的侵蚀事件打断，这些事件可以在时间表短的时间尺度内消除大量的沉积物，而不是地震循环。但是，如此大的侵蚀事件对地震性的作用知之甚少。我们使用QDYN，这是地震周期的准动态数值模型来研究大型侵蚀事件对地震性的影响。滑坡沉积物的进行性疏散是通过瞬时正常应力减少来建模的。我们表明，与地震循环的持续时间相比，持续时间较短的侵蚀事件也可以显着提高地震速率，即使对于较小的压力变化也是如此。此外，与地震成核时间尺度相比，具有较短时期的大型侵蚀事件可以通过触发更多的小事件来改变地震尺寸分布。这些结果表明，大型侵蚀事件可以显着影响地震性，这反过来说明了表面过程对构造学的短期影响。
The long-term erosion of steep landscapes is punctuated by dramatic erosional events that can remove significant amount of sediments within a time-scale shorter than a seismic cycle. However, the role of such large erosional events on seismicity is poorly understood. We use QDYN, a quasi-dynamic numerical model of earthquake cycles to investigate the effect of a large erosional event on seismicity. The progressive evacuation of landslide sediments is modelled by a transient normal stress decrease. We show that erosional events with a shorter duration compared with the duration of a seismic cycle can significantly increase the seismicity rate, even for small stress changes. Moreover, large erosional events with a shorter period compared with the earthquake nucleation time-scale can change earthquake size distribution by triggering more small events. Those results suggest that large erosional events can significantly affect seismicity, illustrating in turn the short-term impact of surface processes on tectonics.
