2020年自动地震速报系统结果分析

Analysis of the results of automatic earthquake information release system in 2020

选取2020年3月1日至12月31日速报地震,通过对比自动地震速报和人工地震速报结果,对自动地震速报系统产出结果进行偏差分析。该时段内自动速报系统共产出国内地震事件216次,漏报49个地震,未发生误报地震。自动速报地震震中位置平均偏差为6.7 km,震级平均偏差为0.15,平均用时119 s。震中位置偏差较大主要由台站分布不均匀、缺少近台、台站空隙角过大及系统自动拾取的震相误差较大所致。震级偏差较大主要是震级转换算法不合理等造成的。自动速报漏报地震与系统在地震定位时初至到时信噪比较低、台站分布不均匀和地震的孤立性等有关。此外,还对全国自动地震速报系统的改进提出了建议。

By comparing the results of the automatic earthquake information release system with those of the manual earthquake information release catalog from Mar.1,2020,to Dec.31,this paper presents an evaluation of China’s automatic earthquake information release system.We calculated overall errors for each automatic location system and analyzed the deviation of the results.During this period,the automatic earthquake information release system reported a total of 216 domestic earthquakes,49 earthquakes were missed,and no earthquake was misreported.The average deviation of the earthquake epicenter location was 6.7 km,the average magnitude deviation was 0.15,and the average time was 119 s.The large deviations in the epicenter location were mainly caused by the uneven distribution of stations,the lack of near stations,and the large arrival time errors automatically picked by the system.The large magnitude deviation was mainly caused by the unreasonable algorithms for the magnitude transformation.The missed earthquakes were due to the low signal-to-noise ratio of first arrivals,uneven distribution of stations,and the isolation of the earthquake when the automatic quick-reporting system locates the earthquake.In addition,this paper also put forward suggestions for the improvement of the national automatic earthquake rapid reporting system.