2011年11月6日3时，美国俄克拉何马州发生了5.6级地震。此次地震是该地区100 多年以来的最大地震，因该区地震活动性低，故需要对此次地震成因开展研究。本文采用CAP(Cut And Paste)方法对该地震分别进行近震、远震以及近远震联合反演，得到了震源机制解与震源深度。其中联合反演得到的机制解参数为:节面Ⅰ:234°/81°/－170°;节面Ⅱ:143°/81°/－9°;震级为MW=5.6。为了验证近震结果的可靠性，采用不同模型对近震数据进行反演测试，发现震源断层面解结果有3°的偏差，震源深度结果有0.5km偏差。CAP结果显示，该地震的质心深度为5.0km左右，属于浅源地震。同时，根据地震震源参数的标度分析，得到破裂区宽度约为7.0km，此次地震破裂区上缘可达1.4km深，下缘深度达8.4km。破裂上缘在该区域井的注水深度范围之内，由此推测该地震可能与当地页岩气开采过程中的注水活动有关。

On November 6，2011，a M5． 6 earthquake occurred in Oklahoma，United States of America，which was the largest earthquake ever recorded in the region over a hundred years． We used CAP method ( CAP，CAPtele，CAPjoint ) to invert focal depth and mechanism of this earthquake，and the result shows that the double-couple solutions of CAPjoint is: 234°，81°，－170° for strike，dip and rake，respectively． The other nodal plane is 143°，81°，－9°． We also applied different models to verify that the CAP inversion result is effective，with 3° deviation in fault plane solution and 0． 5km in focal depth． The result of CAP shows that the centroid depth of this event is 5km，being a shallow earthquake． Based on the scaling law of source parameters， we obtain the 7． 0km width of rupture zone，top to 1． 4km and bottom to 8． 4km，within the range of water-injection depth of wells． This implies that the M5． 6 earthquake is related to waterinjection during shale gas exploration．

中国科学院交叉创新团队以及973 项目(2014CB845901)资助