用远震体波宽频带记录分析1993年10月2日中国新疆南部Mb6．2地震的震源过程

Teleseismic Body Wave Broadband Analysis on Source Process of the Southern Xinjiang Earthquake with Mb6. 2 of 2 October, 1993 in China

远震体波宽频带记录可以用来研究震源参数和破裂过程。利用宽频带地震记录的Ｐ波振幅，可以找到一种较方便地得到一次中强地震的震源机制解的计算方法。１９９３年１０月２日中国新疆南部Ｍｂ６．２地震是一个较为复杂的事件，利用宽频带波形资料和本文提出的一种简化的计算震源两个子事件相对位置的方法分析后认为，这次事件实质上是两次破裂的结果。Ｍｂ６．２地震事件发生前约２．３秒，有另一个小地震事件发生，两个事件之间的相对距离约为５．５ｋｍ，沿破裂面接走向以顺时针方向计，小地震事件相对于主破裂之间的方位是２９５°。对于以上提出的两种算法的结果，我们进行了宽频带地震波形正演拟合检验，证明了算法的有效性。新疆是个多地震地区，本文以新疆南部这次Ｍｂ６．２地震为中心，对方圆２００ｋｍ范围内的历史地震序列作了分析，并对这次地震的构造意义进行了讨论。

Teleseismic body wave broadband records may be used to study source parameters and rupture process. Using the P amplitude of broadband record, it is very convenient to find a possible calculating way to get the source mechanism of a strongly moderate earthquake. The Southern Xinjiang earthquake (Mb6. 2) of 2 October, 1993 is a very complicated event. According to the analysis from both the broadband waveform data and a simple algorithm which is pointed out in this paper, we consider that this event is in a result of rupture twice in fact. Another small guake occurred at about 2. 3 second before the event (Mb6. 2). The relative distance between these two events is about 5. 5 km. Along strike in clockwise, the angle between small event and main event is about 295°in rupture plane.Then we do broadband waveform modelling to examine these two of algorithm. The results show a good validity. Xinjiang is a zone in which earthquake often occurs. In this paper,the historic earthquake sequence in 200km around the Southern Xinjiang earthquake Mb6. 2with is analysized and the tectonic implication of this earthquake is discussed.