Rheological controls on fault loading rates in northern California following the 1906 San Francisco earthquake
Rheological controls on fault loading rates in northern California following the 1906 San Francisco earthquake
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1906 年旧金山地震后，流变学对加州北部断层加载率的控制
DOI：
10.1029/2003gl018903
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发表时间：
2004
影响因子：
5.2
通讯作者：
S. Kenner
中科院分区：
文献类型：
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作者：
S. Kenner
为了估计复杂的多断层系统中的地震危险，有必要了解系统内的应力如何传递。需要准确估计大地震后远场构造运动和震后瞬变引起的加载率。利用 1906 年旧金山地震后观测结果所限制的合理的下地壳流变学，我发现震后松弛可能在同震断层的重新加载中发挥着重要作用，提供了大地震期间释放的 60-80% 的应力。此外，沿邻近断层的震后应力率高度依赖于下地壳/上地幔的几何形状和流变学。这意味着构造加载率的估计也高度依赖于下地壳/上地幔结构。因此，复杂、多断层系统内地震灾害估计的改进取决于对深层结构和流变学的更好理解。
To estimate seismic hazard in complex, multiple fault systems, it is necessary to understand how stresses within the system are transferred. Accurate estimates of loading rate due to far‐field tectonic motion and postseismic transients following large earthquakes are required. Using plausible lower crustal rheologies constrained by observations following the 1906 San Francisco earthquake, I show that postseismic relaxation may play a significant role in reloading the coseismic fault, providing 60–80% of the stress released during great earthquakes. Further, postseismic stressing rates along neighboring faults are highly dependent on the geometry and rheology of the lower crust/upper mantle. This implies that tectonic loading rate estimates are also highly dependent on lower crustal/upper mantle structure. Thus, improvement of seismic hazard estimates within complex, multiple fault systems is dependent on a better understanding of structure and rheology at depth.