利用2014年云南地震验证与研究四川地震预警快速震级估算模型

Research and Validation of Rapid Magnitude Estimation Model for Early Earthquake Warning in the Sichuan Region Using Events from the Yunnan Region, 2014

摘要:

地震预警系统是防震减灾中最为行之有效的方法之一，其中对地震震级的估算是非常重要且困难的。目前，比较成熟的地震震级估计方法包括：基于最大卓越周期（τ_p^max）、特征周期（τ_c）和最大位移幅值（P_d）方法。利用2014年云南地3次大地震主震及余震P波初期部分的信息，验证与研究了四川地区地震预警快速震级估算模型在云南地区的适用性，结果表明3种参数模型均能在短时间内有效地进行震级估算。对于本研究数据库而言，P_d-4 s时窗模型最优，3个参数模型求得的估计震级在大震下均没有出现明显的震级饱和现象。但由于目前难以在短时窗下得到准确的震源/中距，因此推荐在云南地区地震预警系统中使用τ_p^max和τ_c模型来估计震级。

Abstract:

An early earthquake warning system is one of the most effective ways for seismic hazard mitigation, in which earthquake magnitude estimation is the most important and difficult task. Currently, different empirical models have been used to estimate earthquake magnitudes based on τ_p^max, τ_c, or P_d, which are derived using an initial part of P-waves. Here, rapid magnitude estimation model for the Sichuan region was researched and verified based on three large earthquakes in the Yunnan region in 2014. The result showed that three models based on the three parameters above can effectively be used for magnitude estimation in a short time. As for the database in this study, P_d-4 s model worked best among them and all three models did not underestimate the magnitude of large earthquake events. However, it is currently difficult to obtain the accurate epicentral/hypocentral distance in a short time window. Hence, τ_p^max and τ_c models are recommended for use in the Yunnan earthquake early warning system.