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

本项目拟开发一种方法，以准确确定大地震辐射的地震能量，并将其应用于研究俯冲带巨型逆冲断层的应力状态。 辐射地震能量的估计提供了一个重要的约束状态的应力在断层带。 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值可能相差10倍以上。 特别是，从大气环流数据得出的数值往往小于从区域数据确定的数值，据信这是由于复杂的源过程和传播效应造成的。 这项研究将利用来自全球网络的宽带数据和计算真实震源破裂模型的合成波形的最新方法来提高能量确定的准确性; P波和S波都将使用，因为S波携带95%以上的辐射地震能量。

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.