摘要
地震预警(EEW)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:M=f(τ_(max))、M=f(τ_c)和M=f(P_d)方法。本文利用2014年鲁甸主震及余震P波初期部分的信息,研究了地震震级快速估算与三个预警参数的相关性,结果表明三种方法均能在短时间内有效地进行震级估算。对于余震事件,P_d方法出现明显的震级高估现象,而对于主震事件,τ_(max)和τ_c方法离散性较大,P_d方法离散性小,具有明显的优势。由于地震预警系统中的快速震级估算主要针对主震,结果表明在云南地区的地震预警系统中使用P_d参数较为可靠。
Earthquake Early Warning(EEW) system is one of the most effective ways for seismic hazard mitigation,in which predicting earthquake magnitude is one of the most important and difficult tasks.Currently,different empirical models have been used to estimate earthquake magnitude based on M=f(τ_(pmax)) or M = f(τ_c)or M = f(P_d) derived by using initial part of P — waves.We studied the correlation between magnitude and three early warning parameters obtained from the early portion of P—waves for the Ludian earthquake.Three methods can be effectively used for EEW system of magnitude estimation in a short time.For aftershocks,Pd method overestimates the magnitude obviously.But for main shock,τ_(pmax) and τ_c methods are widely dispersed while P_d method discrete small.Because of thinking highly of magnitude estimation in main shock for EEW system,it shows that P_d parameter is more suitable for application in Yunnan earthquake early warning system.
引文
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