河北遥测台网速报震级偏差与量规函数关系的研究

Study on the relationship between magnitude error in quick report and measure function in Hebei Digital Telemeter Seismic Network

选取河北数字遥测地震台网自2001年11月正式运行至2004年6月所记录到的河北省及邻区64次较大的速报地震事件,计算单台震级与多台平均震级的偏差。分析发现,目前所用量规函数在震中距小于70km和大于390km时偏小,认为在大震速报中直接采用震中距70～390km的台站参与计算震级是一种更简便可行的办法;发现平均周期在0.2～0.6s的区间内ΔM相对稳定,因此,在读取最大振幅和周期时,应尽量避免较高频波段或较低频波段,如果是计算机自动读取振幅则应舍掉平均周期小于0.2s和大于0.6s的台站。

By selecting 64 events in quick report for strong earthquakes recorded on Hebei Digital Telemeter Seismic Network from Nov 2001 when the network began to work to June 2004, the errors between magnitude on one station and its average value from many stations are calculated. It is found in analysis that, measure function used at present is relatively small when epicenter distance is shorter than 70 km and longer than 390 km. It is a more simple method in quick report for strong earthquake to use directly the stations in an epicenter distance of 70-390 km when calculating the magnitude. AM is relatively stable in a average period of 0.2s to 0.6 s, so wave bands with much high or low frequency should be avoided in reading the largest amplitude and period, and the stations with average period of smaller than 0.2 s and larger than 0.6 s should be abandoned in ampli.tude auto-reading by computer.