Automated determination of magnitude and source length of large earthquakes using backprojection and P wave amplitudes

作者：Wang, Dun^*; Kawakatsu, Hitoshi; Zhuang, Jiancang; Mori, Jim; Maeda, Takuto; Tsuruoka, Hiroshi; Zhao, Xu

来源：Geophysical Research Letters, 2017, 44(11): 5447-5456.

DOI：10.1002/2017GL073801

• seismic array
• magnitude determination
• disaster mitigation

Fast estimates of magnitude and source extent of large earthquakes are fundamental for disaster mitigation. However, resolving these estimates within 10-20min after origin time remains challenging. Here we propose a robust algorithm to resolve magnitude and source length of large earthquakes using seismic data recorded by regional arrays and global stations. We estimate source length and source duration by backprojecting seismic array data. Then the source duration and the maximum amplitude of the teleseismic P wave displacement waveforms are used jointly to estimate magnitude. We apply this method to 74 shallow earthquakes that occurred within epicentral distances of 30-85 degrees to Hi-net (2004-2014). The estimated magnitudes are similar to moment magnitudes estimated from W-phase inversions (U.S. Geological Survey), with standard deviations of 0.14-0.19 depending on the global station distributions. Application of this method to multiple regional seismic arrays could benefit tsunami warning systems and emergency response to large global earthquakes.

• 出版日期2017-6-16
• 单位中国科学院地质与地球物理研究所兰州油气资源研究中心; 防灾科技学院; 中国地质大学（北京）; 中国科学院地质与地球物理研究所; 地质过程与矿产资源国家重点实验室