【摘要】 新疆乌什台钻孔应变仪在 2 0 0 3年 2月 2 4日伽师 6.8级地震前记录到明显异常 .其特征为 :①异常类别齐全 .震前 1 9个月出现趋势异常 ,震前 5 5天出现短期异常 ,震前 4天出现临震异常 ,并于震前 1个多月出现指数型异常 ;②异常量级大 .最大应变异常量级为 1 .7×1 0 - 5,在乌什台近 2 0年的观测历史中不多见 ;③应变速率波动大 .张压交替变化显著 .依据应变异常量级、指数型异常的出现时间以及异常映震的区域性特点 ,对地震的强度、发震时段以及可能的发震区域有一定程度的预测 .更多还原

【Abstract】 The borehole strain meter at Wushi station recorded obvious anomaly before Jiashi M S=6.8 earthquake occurred on February 24, 2003. Its features are as follows. ① Anomaly types are complete. The trend anomaly, short-term anomaly, short-imminent anomaly and exponential anomaly appeared 19 months, 56 days, 4 days, and more than 1 month before the event, respectively; ② Anomaly is large in magnitude. The maximal magnitude of strain anomaly is 1.7×10 -5, which is rare in the past 20-year observation records at Wushi station; ③ Strain rate fluctuates sharply with obvious alternation of tension and compression. According to the magnitude of strain anomaly, time of exponential anomaly appearance and regional features of recorded anomaly, we could predict the magnitude, occurrence time and potential region to a certain degree.更多还原