福建仙游M_L 5.0震群序列震源参数研究

Analysis on Characteristics of Source Parameters in Fujian Xianyou M_L 5.0 Earthquake Swarm Sequence

应用2012年9月至2015年4月福建区域数字地震台网及边界线附近邻省共享数据台站记录的108个地震事件波形资料,首先采用Atkinson方法求得覆盖福建省较广的地壳平均地震波非弹性衰减,再用Moya方法求得98个台站的场地响应。在此基础上,精确测定得到了福建仙游M_L5.0震群序列M_L≥2.0的45个地震的震源参数,通过定标参数间关系的研究,表明:地震矩M_0随震级M_L的增大而增大,两者之间存在较好的线性关系,统计关系为log M_O=1.06×M_L+9.9;震源半径与震级之间的关系式为:r=112.7×M_L-152.8;拐角频率总体随着震级的增大而变小,线性关系为:f=-3.2×M_L+17.7;应力降随震级的增大总体变大,关系式为:Δσ=1.52×M_L-3.28。

Using the the 108 seismic event waveform data recorded by Fujian regional digital seismic network and sharing data of seismic stations in the neighboring province during September 2012 to April, 2015, the paper firstly used the Atkinson method to calculate the average crustal seismic wave attenuation in Fujian, and then used Moya method to obtain 98 station site response. On the basis of above, the paper calculated the source parameters of 45 earthquakes with M_L≥2.0 of the Fujian Xianyou M_L5.0 earthquake swarm sequence and calibrated the relations among the parameters. The results show that： in single logarithmic coordinates, seismic moment M_0 increase with increasing magnitude ML, there is a good linear relationship as the statistical relationship for Log M_0=1.06×M_L＋9.9; relationship between the focal radius and the earthquake magnitude is r=112.7×M_L-152.8; corner frequency reduce with increasing magnitude ML, the linear relationship is f=-3.2× M_L＋17.7; stress drop increase with increasing magnitude M_L, the linear relationship is Δσ=1.52×M_L-3.28.