用长周期面波波形拟合及P波初动方向估计中等地震的震源机制  

TO ESTIMATE FOCAL MECHANISMS OF MODERATE EARTHQUAKES USING A LONG PERIOD SURFACE WAVEFORM FITTING METHOD AS WELL AS FIRST MOTION SIGNS OF P WAVES

作　　者：马淑田[1] 姚振兴[1] 纪晨 

机构地区：[1]中国科学院地质与地球物理研究所,北京100101

出　　处：《地球物理学报》1999年第6期785-799,共15页Chinese Journal of Geophysics

摘　　要：提出利用周期范围４５—１００ｓ间的面波波形拟合与Ｐ波初动符号相结合，估计中小地震震源机制的方法．给出两个倾滑为主和三个走滑为主的震例．其中最小的是１９９６年１２月１６日北京顺义ＭＬ４．５级地震.比较了１９９６年２月５日云南丽江Ｍｓ６．０级余震的机制解与美国哈佛大学ＣＭＴ结果的相似程度，各震例记录图与理论图的相似程度，以及初动分布与主压力轴Ｐ和主动力轴Ｔ分布区的一致程度．从比较结果看，得到的震源机制解有参考价值，开发的软件有可用性．A procedure that is used to estimate focal mechanisms of moderate and smallearthquakes using surface waveform fitting method and first motion signs of P waves.Two earthquake examples that formed normal faults and three examples that formedstrike-slip faults are given. The smallest earthquake is the one with Mr4.5 occurred onDecember 16, 1996, at Beijing Shunyi. Based on the similarity between the solutionof Yunnan Lijiang Ms6.0 earthquake on February 5,1996, and that of Harvard CMTto the same earthquake, the similarity between waveform of records and that of thesynthetic in the sample earthquakes, as well as the consistency between thedistribution of first motion signs of P waves and P. T regions, the solutions of focalmechanism obtained are valuable, and the software developed is usable.

关 键 词：中小地震 长周期面波 波形反演 震源机制 地震 

分 类 号：P315.3[天文地球—地震学]