Energy Budget of Earthquakes and State of Stress on Subduction-zone Megathrusts

地震的能量收支和俯冲带巨型逆冲的应力状态

• 批准号: 9909371
• 负责人: Hiroo Kanamori
• 金额: $ 11.94万
• 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: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2003-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9909371&HistoricalAwards=false
• 关键词: Energy; Budget; Earthquakes; State; Stress

This project proposes to develop a method to accurately determine seismic energy radiated from large earthquakes, and apply it to study the state of stress on subduction-zone megathrusts. Radiated seismic energy estimates provide an important constraint on the state of stress in fault zones. Unfortunately, the determination of radiated seismic energy is subject to large uncertainties, and estimates by different investigators can differ by more than a factor of 10. In particular, the values derived from teleseismic data tend to be smaller than those determined from regional data, which is believed to result from complex source processes and propagation effects. The research will improve the accuracy of energy determination using broad-band data from global networks and state-of-art methodology for computing synthetic waveforms for realistic source rupture models; both P and S waves will be used, since S wave carry more than 95% of the radiated seismic energy.

该项目提出了一种准确确定大地震辐射地震能量的方法，并将其应用于研究俯冲带巨型逆冲构造的应力状态。辐射地震能量估计对断裂带的应力状态提供了重要的约束。不幸的是，辐射地震能量的确定受到很大的不确定性的影响，不同研究人员的估计可能相差10倍以上。特别是，从远震数据得出的值往往比从区域数据确定的值小，这被认为是复杂的震源过程和传播效应的结果。这项研究将提高利用来自全球网络的宽带数据确定能量的精度，以及用于计算真实震源破裂模型的合成波形的最新方法；将同时使用P波和S波，因为S波携带了95%以上的辐射地震能量。