云南姚安地震序列震源参数研究

摘要

Using the digital waveform data recorded by six temporary digital seismic stations which was closed to the epicenters of the Yao'an M5. 9 and M6. 5 earthquakes in Jaa 15, 2000, applying the methods of the spectrum a-nalysis and Brune' theory, we obtained source spectrum parameters and source parameters of Yao'an earthquake sequence. The result shows that the seismic moments of Yao'an earthquake sequence are between 10 N o m and 1014 N · m, the stress drops are between 0. 005 MPa and 10 MPa, and the source radius is between 50 m and 660 m, and we obtain the relationship between seismic moment M0 and local magnitude ML. With the seismic moment increases the corner frequency reduces, but the stress drop increases. The source radius increases with the magnitude increases, but there is no evidence relationship between source radius and stress drops.%2000年1月15日云南姚安发生5.9级和6.5级地震,利用布设在震中附近的6个流动数字地震台所记录的地震波资料,采用波谱分析和Brune理论的方法,得到姚安地震序列震源谱参数和震源参数.结果表明:地震序列的地震矩在108～ 1014N·m之间,应力降在0.005～ 10 MPa之间,震源半径分布在50 ～660 m之间,并得到地震矩M0和震级ML的关系为:lgM0=8.24+1.4ML.随着地震矩增大应力降增加,拐角频率反而减小；随震级的增大震源半径变大,但震源半径与应力降之间不存在明显的相关关系.