Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.
Department of Earth Sciences, University of Hawaii at Manoa, Honolulu, HI, USA.
Science. 2020 Oct 30;370(6516):605-608. doi: 10.1126/science.abd1690.
Contemporary earthquake hazard models hinge on an understanding of how strain is distributed in the crust and the ability to precisely detect millimeter-scale deformation over broad regions of active faulting. Satellite radar observations revealed hundreds of previously unmapped linear strain concentrations (or fractures) surrounding the 2019 Ridgecrest earthquake sequence. We documented and analyzed displacements and widths of 169 of these fractures. Although most fractures are displaced in the direction of the prevailing tectonic stress (prograde), a large number of them are displaced in the opposite (retrograde) direction. We developed a model to explain the existence and behavior of these displacements. A major implication is that much of the prograde tectonic strain is accommodated by frictional slip on many preexisting faults.
当代地震危险模型依赖于对地壳中应变分布的理解，以及精确检测活动断层广大区域毫米级变形的能力。卫星雷达观测揭示了 2019 年里德克里斯特地震序列周围数百个以前未绘制地图的线性应变集中（或断裂）。我们记录和分析了其中 169 个断裂的位移和宽度。尽管大多数断裂的位移方向与主要构造应力（前伸）一致，但大量断裂的位移方向相反（后退）。我们开发了一个模型来解释这些位移的存在和行为。一个主要的含义是，大部分前伸构造应变是通过许多预先存在的断层上的摩擦滑动来调节的。
