云南地区近震震级与面波震级转换关系研究

Study on the ML and MS of conversation in the Yunnan Regional Digital Networks

摘要:

利用云南地区数字地震台站记录的云南及周边地区2000～2011年4.0级以上可同时测定近震震级ML和面波震级MS的433个地震波形数据，将速度数据进行仿真，即近震震级ML在仿真短周期地震仪DD-1记录上测定，面波震级MS在仿真中长周期地震仪SK记录上测定，对全部人工重新测定的ML和MS，采用线性回归和正交回归方法，得到了它们之间的转换关系式。结果表明，自20世纪70年代使用至今的公式MS = 1.13ML － 1.08与云南地区实际情况存在系统偏差，已不适用于云南地区。考虑到区域差异，认为采用关系式MS = 1.13ML － 0.86作为新的转换关系更合理适用。同时，对云南地震台网和国家地震台网都有记录的地震数据进行对比，发现云南台网和国家台网测定的绝大多数地震ML差值为－ 0.2～ 0.4，差值为0.2的地震数量最多；MS差值为－0.4～0.2，差值为－0.2的地震数量最多。

Abstract:

Seismic station records of M ≥4. 0 earthquakes in the Yunnan Regional Digital Networks in 2000 ～ 2011 were used to determine near earthquake magnitude ML and wave magnitude MS of 433 earthquake waveform data． The speed data were simulated: near earthquake magnitude ML was simulated in terms of short cycle seismographs by DD-1 records，and surface wave magnitude MS in terms of the long cycle seismographs by SK records． All the ML and MS data were then man-checked with linear regression and orthogonal regression and obtain the conversion formula between them． Results showed that the formula MS = 1. 13ML － 1. 08 used since the 1970s may cause problems when applied to the Yunnan region． The adjusted formula of MS = 1. 13ML － 0. 86 is more applicable as the new conversion relationship． Meanwhile，the comparison between the recorded data from Yunnan seismic network and the national seismic network shows the ML difference of － 0. 2 ～ 0. 4 in most of these data with 0. 2 as the majority and MS difference between － 0. 4 ～ 0. 2 with － 0. 2 as the majority．