利用CAP方法快速计算云南地区中小地震震源机制解  

Fast CAP calculation of focal mechanism of moderate and small earthquake in the Yunnan area

作　　者：杨军[1] 苏有锦[2] 陈佳[1] 叶泵[1] 李孝宾[1] 金明培[1] 王宝善[3] 

机构地区：[1]中国地震局滇西地震预报实验场办公室 [2]云南省地震局,昆明650224 [3]中国地震局地球物理研究所,北京100081

出　　处：《中国地震》2014年第4期551-559,共9页Earthquake Research in China

基　　金：地震行业专项"滇西地区深部介质变化主动监测技术研究(地下明灯1)"(201208004);中国地震局地震观测与地球物理成像重点实验室开放基金(SOGI2013FUDA02)共同资助

摘　　要：地震的震源机制解是反应区域应力场的重要参数,充分利用数量众多的中小地震将有助于获得更高精度的区域应力场分布。本文以滇西地震预报实验场下关虚拟测震台网为例,介绍了利用虚拟台网产出数据,采用CAP方法计算中小地震震源机制解的流程,并将该方法应用于计算云南地区2013年2月-2014年2月间MS≥3.0的64次中小地震震源机制解。结果显示：①本文给出的方法为一种半自动处理方法,该方法可以在地震速报结果之后45分钟之内给出震源机制解,分析认为影响震源机制解快速产出的主要因素是格林函数库的建立和编程实现标注P波到时的全自动化;②云南地区中小地震震源机制解以走滑为主,但在香格里拉和洱源地区有少量正断层地震存在,位于研究区域内中小地震P轴主应力方向在川滇菱形块体南部以北北西-南南东为主,而在印支板块则主要以北北东-南南西为主。Earthquake focal mechanism is an important parameter to reflect the regional stress field. The study of a large number of small and moderate earthquakes will help to obtain more accurate distribution of regional stress field. The paper took the virtual seismic network of Western Yunnan Earthquake Prediction Study Area as an example,and introduced the output processes of data by virtual network,calculated small and moderate earthquake focal mechanism with the CAP method,and applied this method in the focal mechanism calculation of 64 MS≥3. 0 small and moderate earthquakes that occurred in the Yunnan area during the time of February 2013 to February 2014. The results indicate that： ① The method introduced in this paper is a semiautomatic processing method. This method can give out focal mechanism solution in 45 minutes after the earthquake quick report. The analysis shows that the main factors that influence fast output of focal mechanism solution are the establishment of Green ＇s function library and the automatic marking of the arrival time of P wave.② In Yunnan area,the small and moderate earthquake focal mechanisms are mainly of strike-slip type. However,there is a small number of normal faults in the Shangri-La and Eryuan county area. The P axis azimuth of small and moderate earthquake focal mechanisms in the south of Sichuan and Yunnan rhombus block is mainly NNW-SSE,while in the Indosinian plate it is mainly NNE-SSW.

关 键 词：CAP方法 云南地区 中小地震 震源机制 

分 类 号：P315.3[天文地球—地震学]