四川地区同一地震垂直向与水平向震级测量的差异性分析

Analysis on the Seismic Magnitude Difference between Vertical and Horizontal Components in Sichuan Province

选取四川数字测震台网记录的四川及周边50 km以内地区2014～2015年达到速报范围(M_L≥3. 6)的174个(后续研究加入了2013年能测量MS的12个地震)地震波形数据,在仿真与不仿真情况下分别测定水平向和垂直向的M_L与MS震级,得到696个震级数据。分析同一地震水平向和垂直向测定的震级值得到结论如下:在不仿真情况下,水平向测量M_L比垂直向测量的M_L偏大,其中偏大0. 2级的占85. 62%;在仿真情况下,水平向测量比垂直向测量的M_L偏大,其中偏大0. 2级的占82. 19%,仿真与不仿真情况下测得的M_L存在线性关系;在不仿真和仿真基式情况下测量的MS震级,水平向测量与垂直向测量震级差值略大,偏差范围为-0. 1～0. 3,其中偏大0. 1的样本数最多。

The waveform data of 174 seismic events recorded by Sichuan Digital Seismic Networks in Sichuan province and its bonder areas within 50 km from 2014 to 2015,in which the seismic events reaches the rapid report magnitude range of M L3.6,are selected and 12 earthquakes that could be measured by M s in 2013 are also added into waveform data.By using the simulation and un-simulation methods,we use horizontal and vertical components of these waveform data to determine every earthquake magnitudes M s and M L separately.696 new seismic magnitudes are got.We then analyze these 696 magnitudes and find that the earthquake magnitude M L calculated by the horizontal component is larger 0.2 seismic unit than that calculated by vertical component without simulation.On the other hand,the earthquake magnitude calculated by horizontal component is larger 0.2 seismic unit than that calculated by vertical component in simulation.There is a linear relationship between simulation and un-simulation circumstances.The magnitude difference between horizontal and vertical is little bit.