Scaling of maximum observed magnitudes with geometrical and stress properties of strike‐slip faults
Scaling of maximum observed magnitudes with geometrical and stress properties of strike‐slip faults
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根据走滑断层的几何和应力特性缩放最大观测震级
DOI：
10.1002/2015gl066478
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发表时间：
2015
影响因子：
5.2
通讯作者：
G. Dresen
中科院分区：
文献类型：
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作者：
P. Martínez‐Garzón;M. Bohnhoff;Y. Ben‐Zion;G. Dresen
我们测试了沿沿着27个走滑断层观测到的最大地震震级之间的潜在比例关系，这些断层具有各种属性，包括累积位移、映射的断层长度、孕震厚度、滑动速率以及断层走向与最大水平应力之间的角度。对于75 - 80%的数据集，观测到的最大标量矩与孕震厚度和累积位移或映射的断层长度的乘积成比例。这些断层中的大多数断层的滑动速率> 5 mm/yr（板间断层），累积位移> 10 km，与最大水平应力方向的夹角相对较大。其余20 - 25%的地震发生在距板块边界一定距离处，滑动速率<5 mm/yr，累积位移<10 km，与最大水平应力成45 °。这些地震的震级比以前的地震大，可能是因为更大的应力降。最可能的解释的结果是，最大破裂长度，因此地震震级，与累积位移和断层面长度。结果还表明，渐进断层平滑可能会导致同震应力下降减少。
We test potential scaling between observed maximum earthquake magnitudes along 27 strike‐slip faults with various properties including cumulative displacement, mapped fault length, seismogenic thickness, slip rates, and angle between fault strike and maximum horizontal stress. For 75–80% of the data set, the observed maximum scalar moment scales with the product of seismogenic thickness and either cumulative displacement or mapped fault length. Most faults from this population have slip rates >5 mm/yr (interplate faults), cumulative displacement >10 km, and relatively high angles to the maximum horizontal stress orientation. The remaining 20–25% population involves events at some distance from a plate boundary with slip rate <5 mm/yr, cumulative displacements <10 km, and ≈ 45° to the maximum horizontal stress. These earthquakes have larger magnitudes than the previous population, likely because of larger stress drops. The most likely interpretation of the results is that the maximum rupture length, and hence earthquake magnitudes, correlates with the cumulative displacement and the fault surface length. The results also suggest that progressive fault smoothing may lead to decreasing coseismic stress drops.