Dual control of fault intersections on stop-start rupture in the 2016 Central Italy seismic sequence
Dual control of fault intersections on stop-start rupture in the 2016 Central Italy seismic sequence
复制标题
DOI：
10.1016/j.epsl.2018.07.043
复制
发表时间：
2018-10
影响因子：
5.3
通讯作者：
R. Walters;L. Gregory;L. Wedmore;T. Craig;K. McCaffrey;M. Wilkinson;J. Chen;Zhenhong Li;J. Elliott;H. Goodall;F. Iezzi;F. Livio;A. Michetti;G. Roberts;E. Vittori
中科院分区：
文献类型：
--
作者：
R. Walters;L. Gregory;L. Wedmore;T. Craig;K. McCaffrey;M. Wilkinson;J. Chen;Zhenhong Li;J. Elliott;H. Goodall;F. Iezzi;F. Livio;A. Michetti;G. Roberts;E. Vittori
大型大陆地震必然涉及多个断层或断层段的破坏。但是，这些同样的临界应力系统有时会在几天或几年的小地震中失败。这两种破坏模式对地震危险性有着截然不同的影响，目前还不知道为什么断层系统有时会以一种或另一种模式发生破坏，也不知道是什么控制了长期地震序列中滑动的终止和重新开始。对地震序列的现代观测的缺乏阻碍了我们迄今为止的理解，但2016年8月至11月在意大利中部发生的一系列三次Mw> 6地震代表了一个独特的观测良好的例子。在这里，我们利用大量的大地测量，地震和现场数据来了解序列的时空演变。我们的研究结果表明，主要和辅助故障之间的交叉点控制的程度和终止的破裂，在每个事件的序列中，和流体扩散，引导沿着这些相同的故障交叉点，也可能决定了破裂重新启动的时间。这种地下结构对地震序列中断续破裂的双重控制可能是常见的;今后的工作应集中于调查其普遍性。
Large continental earthquakes necessarily involve failure of multiple faults or segments. But these same critically-stressed systems sometimes fail in drawn-out sequences of smaller earthquakes over days or years instead. These two modes of failure have vastly different implications for seismic hazard and it is not known why fault systems sometimes fail in one mode or the other, or what controls the termination and reinitiation of slip in protracted seismic sequences. A paucity of modern observations of seismic sequences has hampered our understanding to-date, but a series of three M w> 6 earthquakes from August to November 2016 in Central Italy represents a uniquely well-observed example. Here we exploit a wealth of geodetic, seismological and field data to understand the spatio-temporal evolution of the sequence. Our results suggest that intersections between major and subsidiary faults controlled the extent and termination of rupture in each event in the sequence, and that fluid diffusion, channelled along these same fault intersections, may have also determined the timing of rupture reinitiation. This dual control of subsurface structure on the stop-start rupture in seismic sequences may be common; future efforts should focus on investigating its prevalence.