利用防灾台网的单台波形数据确定地震位置的方法及实践

Methods and Practices of Earthquakes Locating by Single Station Waveform Data of Telemetry Network of Institute of Disaster Prevention

为提高防灾台网的地震监测水平,并发挥震后地震参数速报和应急的作用,尝试改进单台定位方法、仅采用防灾台网观测数据对周围中小地震进行定位。先利用单台对地震进行定位,然后将多台对单个地震定位结果取平均值后得到P波初动定位结果。在使用与防灾台网相同地震数据前提下,对2018年1月—2019年12月记录的17次近震定位(震中距<500km,ML>2),结果表明:对于网缘和周边90 km内的近震,P波初动定位精度优于防灾台网的盖革法定位结果,采用的P波初动定位方法适用于防灾小孔径台阵网缘地震和周边90 km内的地震。对于网外90~500 km的地震,两种定位方法精度均不高,但P波初动定位偏差稍小于防灾台网定位。

In order to improve seismic monitoring ability of the Telemetry Network of Institute of Disaster Prevention(TNIDP)and to play its role of rapidly report the earthquake parameters after an earthquake for emergency response,we try to improve the single station positioning method and locate the small-medium earthquakes only using the observed seismic waveform data of TNIDP.First,we use a single station to locate the earthquake,and then take the average value of the location results of multiple stations for a single earthquake to obtain the P wave initial motion positioning result.Under the premise of using the same earthquake data as TNIDP,we located the 17 local earthquakes recorded from Jan.,2018 to Dec.,2019(epicenter distance<500km,ML>2).As the results show,for local earthquakes within 90 km at the edge and the surrounding area of TNIDP,the positioning accuracy of P-wave initial motion is better than that of Geiger method of TNIDP,indicating that the P-wave first motion locating method used in this paper is more suitable.For earthquakes of 90~500 km away from the TNIDP,the accuracy of the two methods is not high,but the positioning deviation of P-wave initial motion is slightly less than that of TNIDP.