2012年5月28日唐山MS4.8地震震源机制解和震源深度精确测定

摘要

To get accurate seismic parameters,we used the broadband waveforms data of the Tangshan Ms4.8 earthquake on March,28,2012 and the cut-and-paste (CAP) method to obtain the best focal mechanism.And then,combined with a variety of depth phases,we accurately determined the focal depth.The results show that,the earthquake is tension and strike slip.The best double couple solution is 139°,79° and-17° for strike,dip and slip angles respectively for one nodal plane,and 232°,73° and-169° for another.The estimated focal depth is 10 km.According to the epicenter and the focal mechanism,This earthquake likely occurred on the Tangshan Fault.%本文采用2012年5月28日唐山MS4.8地震的宽频带波形资料,利用CAP方法反演得到该地震震源机制解和震源深度,在此基础上,结合多种深度震相对震源深度进行精确测定.结果显示:唐山MS4.8地震是略带正断分量的走滑型地震.最佳双力偶解节面Ⅰ走向139°、倾角79°、滑动角-17°;节面Ⅱ走向232°、倾角73°、滑动角-169°;最佳震源深度为10 km,属于浅源地震.从震中位置和震源机制解来分析,此次地震发震断层可能为唐山断裂.