Partitioned Off-Fault Deformation in the 2016 Norcia Earthquake Captured by Differential Terrestrial Laser Scanning
Partitioned Off-Fault Deformation in the 2016 Norcia Earthquake Captured by Differential Terrestrial Laser Scanning
复制标题
差分地面激光扫描捕获的 2016 年诺尔恰地震中的分区断层变形
DOI：
10.1029/2018gl080858
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发表时间：
2019
影响因子：
5.2
通讯作者：
Wedmore L
中科院分区：
文献类型：
--
作者：
Wedmore L
同震断层滑动的现场测量结果往往不同于卫星大地测量得出的地表滑动模型。由于许多大地测量技术不能很好地成像近断层形变，量化这些差异具有挑战性。我们使用迭代最近点算法来区分地震前和地震后的地面激光扫描点云，以揭示2016年意大利中部Mw6.6 Norcia地震中浅层断层滑动引起的地表变形的厘米级图案。沿断层的地面激光扫描偏移量是恒定的，并与平均野外测量结果相匹配。84%的垂直位移发生在离散的断裂带上，16%的变形分布在一个4米宽的狭窄带上。相反，水平形变分布在8米宽的区域内，大约50%的伸展被容纳为断层外变形(OFD)。厘米尺度的形变观测表明，水平和垂直同震的OFD是分割的，在这种情况下，OFD以水平形变为主。
Field measurements of coseismic fault slip often differ from surface slip models derived from satellite geodesy. Quantifying these differences is challenging as many geodetic techniques inadequately image near‐fault deformation. We use an iterative closest point algorithm to difference preearthquake and postearthquake terrestrial laser scanning point clouds to reveal centimeter‐scale patterns of surface deformation caused by shallow fault slip in the 2016 Mw6.6 Norcia (Central Italy) earthquake. Terrestrial laser scanning offsets are constant along the fault and match average field measurements. Eighty‐four percent of vertical displacement occurs on a discrete fault zone, with 16% of deformation distributed across a narrow zone <4 m wide. In contrast, horizontal deformation is distributed over an 8‐m‐wide zone with approximately 50% of extension accommodated as off‐fault deformation (OFD). The centimeter‐scale observation of deformation shows that horizontal and vertical coseismic OFD is partitioned—in this case, OFD is dominated by horizontal deformation.