乌什台两次地震钻孔应变异常的对比研究

2003年2月24日至12月1日先后在伽师和昭苏县境内发生了Ms6．8与Ms6．0两次地震，新疆乌什台距两次地震震中200多千米，震前钻孔应变仪均记录到异常。其异常的不同点是；伽师地震前有趋势异常，昭苏地震前则无；伽师地震的应变异常量级大于昭苏地震异常一个数量级；伽师地震异常类型齐全（趋势、短期、临震异常、指数型异常），昭苏地震只有短期和临震异常。其异常的相同点是：短期异常形态、应变性质、异常出现时间基本相当；临震异常的出现时间及波动性基本相同。

COMPARISON BETWEEN BOREHOLE STRAIN ANOMALIES OF TWO EARTHQUAKES RECORDED AT WUSHI STATION

On Feb 24~(th), and Dec.1st 2003 two earthquakes of M_S 6.8 and 6.0 occured in Jiashi and (Zhaosu), Xinjiang region. Located about 200 kilometers from both the epicenters, the borehole strain anomalies at Wushi station had been recorded. The difference between these two anomalies is that there was trend anomaly before the Jiashi event while there wasn't before Zhaosu quake and the level of strain anomaly of the former is one order higher than that of the latter. Besides, the anomaly from Jiashi quake had complete styles:trend, short-term, the impending and exponential anomaly, the Zhaosu quake only had two styles: short-term and the impending anomaly.In the other hand, the anomalies of two earthquakes had something in common: the configuration,strain characteristics and occuring time of the short-term anomaly. Besides, the occuring time and fluctuant characteristics of both the impending anormalies were similar to each other.