最大卓越周期估算震级方法的优化研究  

Study on the magnitude estimation based on the optimized maximum predominant period

作　　者：赵庆旭 王延伟 刘娟 莫红艳[1] 曹振中[1] ZHAO Qingxu;WANG Yanwei;LIU Juan;MO Hongyan;CAO Zhenzhong(Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin University of Technology,Guilin 541004,China)

机构地区：[1]桂林理工大学广西岩土力学与工程重点实验室,桂林541004

出　　处：《世界地震工程》2023年第2期200-212,共13页World Earthquake Engineering

基　　金：国家自然科学基金项目(51968016,51968015);广西岩土力学与工程重点实验室主任基金(桂科能19-Y-21-8)。

摘　　要：震级估算是地震预警系统(EEWs)的核心任务。基于最大卓越周期参数(τ^(p)_(max))的震级估算方法被广泛研究和应用,但τ^(p)_(max)计算细节被忽视,导致τ^(p)_(max)的震级估算效果存在较大的差异。为此,利用日本的大量井下强震记录,对τ^(p)_(max)计算涉及的滤波范围、滤波阶数和平滑系数的设置进行优化,提出了τ^(p)_(max)的优化计算方法,即滤波范围选用高通0.001 Hz,滤波阶数为1阶,平滑系数取0.95。利用日本和智利的初至3~6 s P波对比分析优化后的τ^(p)_(max)和优化前的τ^(p)_(max)以及c的震级估算效果,结果表明:优化后的τ^(p)_(max)与震级的相关性和震级估算的误差均好于优化前的τ^(p)_(max)和c。本文给出的τ^(p)_(max)优化计算方法,可以显著地改善τ^(p)_(max)在EEWs中的震级估算效果。Magnitude estimation is a key task of earthquake early warning systems(EEWs).The magnitude estimation method based on the maximum predominant period parameter(τ^(p)_(max))has been widely studied and applied,but the details of τ^(p)_(max) calculation have been ignored,resulting in large differences in magnitude estimation.Therefore,a large number of strong downhole ground motion records from Japan are used to optimise the settings of the filter range,filter order and smoothing coefficient involved in the τ^(p)_(max) calculation,and the optimal calculation method for τ^(p)_(max) is proposed.The optimal calculation is that the filter range is 0.001 Hz high pass,the filtering order is 1 and the smoothing coefficient is 0.95.The magnitude estimation performance of the optimized τ^(p)_(max),the pre-optimized τ^(p)_(max) and the average period parameter(c)calculated by initial 3-6 s P waves of Japan and Chile was tested.The results show that,the correlation between the optimized τ^(p)_(max) and magnitude and the error of the magnitude estimation of the optimized τ^(p)_(max) are better than those of pre-optimized τ^(p)_(max) and c.The proposed optimal calculation method of τ^(p)_(max) can significantly improve the magnitude estimation of τ^(p)_(max) for EEWs.

关 键 词：地震预警 震级估算 最大卓越周期 KiK-net 

分 类 号：P315.9[天文地球—地震学]