Relation Between 3-D Structure, Mechanism and Dynamic Characteristics of Earthquakes in the Northridge Area

北岭地区地震三维结构、机制与动力特征的关系

• 批准号: 9416120
• 负责人: Hiroo Kanamori
• 金额: $ 5.91万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-15 至 1995-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9416120&HistoricalAwards=false
• 关键词: Relation; Between; Structure; Mechanism; Dynamic

9416120 Kanamori This research is to investigate the relationship between the 3-D crustal structure, the fault geometry and the dynamic characteristics of the Northridge earthquake sequence. The 1994 Northridge earthquake occurred on a south-dipping fault beneath the Transverse Ranges, in striking contrast to the 1971 San Fernando earthquake which occurred on a north-dipping fault. This will investigate why the two faults are segmented like this (north vs. south), and what prevented the rupture of the Northridge earthquake from extending further to the west. Since the Transverse Ranges involve many active structures formed under a regional north-south compressional stress system, a much larger earthquake than the Northridge earthquake could occur if the system, a much larger earthquake than the Northridge earthquake could occur if the rupture extended over many segments of faults. The work will also involve investigation of the variation of dynamic characteristics (waveform, stress drop, energy-moment ratio) of the major aftershocks in relation to the 3-D structure. This project is a contribution to the National Earthquake Hazard Reduction Program and is supported by the Northridge Earthquake Emergency Appropriation. ***

小行星9416120 本研究旨在探讨北岭地震序列的三维地壳结构、断层几何学与地震动力学特征之间的关系。 1994年北岭地震发生在横贯山脉下的南倾断层上，与1971年圣费尔南多地震发生在北倾断层上形成鲜明对比。 这将调查为什么两个断层是这样分割的（北对南），是什么阻止了北岭地震的破裂进一步向西延伸。 由于横贯山脉包含许多在区域南北挤压应力系统下形成的活动构造，如果该系统破裂，可能发生比北岭地震大得多的地震，如果破裂延伸到许多断层段，可能发生比北岭地震大得多的地震。 这项工作还将涉及调查与三维结构有关的主要余震的动态特征（波形、应力降、能量-力矩比）的变化。 该项目是对国家减少地震危险计划的贡献，并得到北岭地震紧急拨款的支持。 ***