虚拟地震学家(VS)方法在中国地震台网中的测试和评估

Testing and Evaluation of Virtual Seismologist(VS)Method in China Seismological Network

摘要:

建设中国地震预警系统是国家地震烈度速报与预警工程的主要内容，国内外学者通过对预警系统中确定地震参数的方法研究，发现实时确定准确震级这一问题最具挑战性，亟需一种可用的震级实时测定方法用于建设中国的地震预警系统。本文简要介绍了虚拟地震学家(VS)方法，描述了VS方法在中国地震台网用于实时测定地震参数的软件的实现流程，剖析用该方法实时确定2019年6月17日四川长宁6.0级地震的M_VS的过程。通过实时在线测定134个M≥3.0地震的M_VS和回放事件波形测定24个M≥5.0地震的M_VS，对VS方法进行测试，评估其可用性。结果表明，使用VS方法实时确定的M_VS变化平稳，可用性较好。当3个台站的P波信息可用时，第一次测定M_VS时偏差δ的平均值为0.32，δ≤0.5的占79%，平均用时为20s。随着时间的推移，更多可用台站及波形的使用可有效提升测定M_VS准确度。该方法在中国地震台网的应用具有适用性和可行性，是一种可选的实时确定震级的方法，在地震预警中具有较好的应用潜力。

Abstract:

The construction of Chinese earthquake early warning system is the main content of the national earthquake intensity quick report and early warning project. In the study and practice on the methods of determining earthquake parameters in the early warning system, scholars in and abroad found that the problem of the determination of the accurate magnitude in real time is challenging. Therefore, there is an urgent need for available real-time magnitude measurement methods to be used in the construction of Chinese earthquake early warning system. This paper briefly introduces the virtual seismologist(VS)method, describes the implementation process of VS method in the software for real-time determination of seismic parameters in China seismic network, and analyzes the process of using this method to determine the M_VS of Sichuan Changning M6.0 earthquake on June 17, 2019. Using the data of China seismic network constructed by the tenth five year plan project, the M_VS of 134 earthquakes with M≥3.0 and 24 earthquakes with M≥5.0 are measured by real-time online measurement and playback event waveform. The VS method is tested and its availability is evaluated. The results show that the M_VS determined in real time by VS method changes smoothly and has good availability. When the P-wave information of three stations is available, M_VS is measured for the first time, the average value of deviationδis 0.32, the number of earthquakes with δ≤0.5 accounted for 79%, and the average time was 20s. As time goes on, the use of more stations and available waveforms can effectively improve the accuracy of M_VS measurement. The application of this method in China seismic network is applicability and feasibility. It is an optional method for determining earthquake magnitude in real time, and has good application potential in earthquake early warning.