利用波形反演方法,研究并确定了2004年3月24日发生在内蒙古东乌珠穆沁旗与西乌珠穆沁旗交界处地震的震源机制及深度。近震波形对震源机制有很好的约束,而远震体波对于震源深度分辨率很高,因此综合利用了近震和远震波形数据。对于近震宽频带波形记录,用CAP方法反演震源机制解。利用远震直达P波、pP波和sP波的到时能较好的确定震源深度。综合利用近震宽频带波形和远震体波波形记录,反演得出2004年03月24日地震为逆冲型,震级为Mw5.3。其两个节面分别为:节面Ⅰ的走向、倾角、滑动角分别为147°、22°、87°,节面Ⅱ的走向、倾角、滑动角分别为330°、68°、91°;震源深度为(12±2)km,是一个典型的浅源上地壳地震。与前震序列对比,节面Ⅰ是可能的发震构造。
Using waveform inversion method, we studied the focal mechanism and depth of 2004-03-24 earthquake occurred in Inner Mongolia (Latitude, Longitude ). Local waveform has better constraints on focal mechanism, while teleseismic waveform has high resolution on source depth. Both methods were employed to invert source parameters. Focal mechanism was inverted by CAP method. The inverted depth was confirmed by teleseismic P wave modeling. The earthquake is determined as a thrust event with focal planes as 330-68-91 and 147-22-87, magnitude of MwS. 3 and focal depth.- 12 2 km. So, the earthquake occurred in upper crust instead of 30 km at depth as reported by many other papers.