湖南地区重复地震识别及其在数字地震台网定位评价中的应用

Recognition of repeating earthquakes in Hunan area and its application to seismic network location evaluation

本文基于湖南地震台网2009—2022年间记录的778个地震事件波形及其观测报告,开展波形互相关分析,设定重复地震筛选条件为:同时被至少3个台站记录,且互相关系数不低于0.8。共识别出重复地震对149组,占地震总数的14.5%。通过研究这些重复地震对,对湖南地震台网的定位水平和震相拾取精度进行评估。结果表明:湖南地震台网的水平定位误差约为3.5 km,垂直定位误差约为3 km;P_(g)和S_(g)震相的拾取误差分别约为0.4 s和0.7 s。此外,湖南地区定位误差没有明显的区域差别,除常德地区外,误差值基本在4 km以内。

Based on 778 earthquakes(2009—2022)and their observation reports recorded by the Hunan Seismic Network,through the analysis of the cross-correlation of the waveforms,149 repeated earthquake pairs were identified which were recorded at least 3 stations with cross-correlation coefficients no less than 0.8.After obtaining these data,the location errors and phase picking errors of the Hunan Seismic Network were statistically analyzed.The results show that the horizontal location error is around 3.5 km,and the vertical location error is around 3 km.The P_(g)and S_(g) phase picking errors are about 0.4 s and 0.7 s,respectively.There is no significant difference in location error in Hunan region,except for the Changde area,where the error is basically within 4 km.