Damage zone heterogeneity on seismogenic faults in crystalline rock; a field study of the Borrego Fault, Baja California
Damage zone heterogeneity on seismogenic faults in crystalline rock; a field study of the Borrego Fault, Baja California
复制标题
结晶岩发震断层损伤带的非均质性；
DOI：
10.1016/j.jsg.2020.104016
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发表时间：
2020
影响因子：
3.1
通讯作者：
F. Ostermeijer
中科院分区：
文献类型：
--
作者：
G. Ostermeijer;T. Mitchell;F. Aben;M. T. Dorsey;John Browning;T. Rockwell;J. Fletcher;F. Ostermeijer
大断层周围的复杂裂缝损伤常被简化为裂缝密度随距离的指数或幂律衰减。这些数据集中的噪声归因于大的辅助故障或随机的自然变化。通过对Borrego断层（下加利福尼亚）损伤带的实地研究，结合毫米分辨率构造制图和点采样，我们表明，这种变化是系统损伤不均匀性的表达。博雷戈断层由NW和SE两部分组成，在2010年El Mayor-Cucapah地震期间破裂。沿沿着8条线性断层垂直断面和高分辨率68 m2构造图测量的裂缝密度显示幂律衰减，并确定NW和SE段的下盘损坏区宽度分别为~85 m和~120 m。裂缝密度的方差随距离呈反指数关系衰减，在~16 m处与背景方差成反比。对高分辨率裂缝图的空间分析显示，在米和分米尺度上，高强度和低强度的集群呈片状分布。我们将这些尺度上的高强度集群归因于较小的次级断层（长度为101米，位移为10−2-10− 1米）之间的相互作用所导致的局部复杂性。高强度和低强度集群之间的裂缝密度差异随着距断层的距离而减小，表明露头尺度损害不均匀性的系统变化。基于这些观察，我们提出了一个修正模型的损伤区的增长，包括增长的异质性。
Complex fracture damage around large faults is often simplified to fit exponential or power law decay in fracture density with distance from the fault. Noise in these datasets is attributed to large subsidiary faults or random natural variation. Through a field study of the Borrego Fault (Baja California) damage zone, combining mm-resolution structural mapping and point sampling, we show that such variations are the expression of systematic damage heterogeneity. The oblique-slip Borrego Fault comprises NW and SE segments that ruptured during the Mw7.2 2010 El Mayor-Cucapah earthquake. Measurements of fracture density along eight linear fault-perpendicular transects and from a high-resolution 68 m2structural map display a power law decay and define footwall damage zone widths of ~85 m and ~120 m for the NW and SE segments respectively. Variance in fracture density decays with distance following an inverse exponential relationship, to background variance at ~16 m. Spatial analysis of the high-resolution fracture map reveals a patchy distribution of high- and low-intensity clusters at metre- and decimetre-scales. We attribute high-intensity clusters at these scales to local complexity caused by interactions between minor subsidiary faults (101m length and 10−2-10−1m displacement). Fracture density differences between high- and low-intensity clusters decrease with distance from the fault, demonstrating a systematic change in outcrop-scale damage heterogeneity. Based on these observations we present a revised model for damage zone growth including growth of heterogeneity.
影响因子：
3.1
作者：
D. Healy;R. Rizzo;D. Cornwell;N. Farrell;Hannah Watkins;N. Timms;E. Gomez‐Rivas;Michael C. Smith-Michael-C.-Sm
通讯作者：
D. Healy;R. Rizzo;D. Cornwell;N. Farrell;Hannah Watkins;N. Timms;E. Gomez‐Rivas;Michael C. Smith-Michael-C.-Sm
DOI：
10.1002/2015jb012542
发表时间：
2016-04
期刊：
Journal of Geophysical Research: Solid Earth
影响因子：
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作者：
F. Aben;M. Doan;T. Mitchell;R. Toussaint;T. Reuschlé;M. Fondriest;J. Gratier;François Renard
通讯作者：
F. Aben;M. Doan;T. Mitchell;R. Toussaint;T. Reuschlé;M. Fondriest;J. Gratier;François Renard