Analysis of the 1994 Northridge Earthquake Aftershocks Using Micropolar Continuum Theory

利用微极连续体理论分析 1994 年北岭地震余震

• 批准号: 9416318
• 负责人: Jeffrey Unruh
• 金额: --
• 依托单位: William Lettis & Associates Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-01-15 至 1996-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9416318&HistoricalAwards=false
• 关键词: Analysis; 1994; Northridge; Earthquake; Aftershocks

9416318 Unruh This study will analyze the aftershocks of the January 17, 1994 Northridge earthquake to obtain distributed seismogenic deformation and t test existing models of uplift and folding above blind thrust faults. Detailed studies of recent blind thrust earthquakes have shown that significant deformation of the hangingwall of the fault occurs by slip on small faults at a high angle to bedding, and not just by bedding-plane slip as the models imply. Another possible reason for departure from the standard model is that the thrusts beneath the Los Angeles and San Fernando Valleys are rooted in crystalline basement rocks, rather than in sedimentary rocks for which the model was originally developed. The analysis will use patterns of seismic P and T axes to obtain seismogenic strain rates and the rotational component (vorticity), which will then be compared with the model prediction. The results will enhance understanding of deformation associated with blind thrusts, and will be therefore test the ability of the existing models to predict behavior of the crust during blind thrust earthquakes.

9416318这项研究将分析1994年1月17日北岭地震的余震，以获得分布的孕震形变，并检验现有的在盲冲断层上方隆起和褶皱的模型。对近期隐伏逆冲地震的详细研究表明，断层上盘的显著变形是通过与顺层成高角的小断层上滑动而发生的，而不是像模型所暗示的那样仅仅是顺层滑移。背离标准模型的另一个可能原因是，洛杉矶和圣费尔南多山谷下面的冲突体植根于结晶的基底岩石，而不是最初为其开发模型的沉积岩。分析将使用地震P轴和T轴的模式来获得孕震应变率和旋转分量(涡度)，然后将其与模型预测进行比较。这一结果将加强对与盲冲有关的形变的理解，因此将检验现有模型在盲冲地震期间预测地壳行为的能力。