【摘要】 以20多年来新疆地区的18个地下流体监测点的资料为基础,沿着“异常与震中”这一主线,对新疆地区的16次5级地震、4次7级以上地震及1个6级强震群的前兆异常特征进行了定量的统计与分析。结果表明,源、场、远兆异常有如下特征:异常空间展布不均,源兆空间内异常监测点展布"密集"、异常比例可达90%;而场兆空间展布“稀疏”、“分散”,异常比例一般在45%~53%;而远兆则是更加“稀疏”和“零星”,异常比例统计为25%。异常起始时间不同,源兆异常时间以中期为主;中强震场兆异常时间以中短期、特别是短期为主;强震场兆以中期异常为主;而强震远兆则也以中期异常为主。异常形态不同,源兆中期异常及强震场兆中期异常一般是趋势性大幅度升高变化为主,且以化学测项为多,油气探井以井喷形式予以表现;而中强震场兆异常,一般表现为幅度明显的短期内的负异常、脉冲突跳、短期内的高值上升、阶变及年变化规律被打破等;强震远兆特征则基本上表现为少数测点、测项的大幅度中期异常及个别测项的临震大幅度突跳现象,油气探井则也以剧烈井喷形式予以表现。更多还原

【Abstract】 Based on the data recorded by 18 ground fluid monitoring stations in Xinjiang Uygur Autonomous Region for 20 years,along the main line of anomalies and earthquake epicenters,the statistics and analysis on characteristics of precursory anomalies of 16 M5 earthquakes,4 earthquakes with M>7 and 1 M6 strong earthquake swarm are conducted.The results show that the focal,field and remote precursory anomalies are of the following characteristics:The spatial distribution of anomalies is inhomogeneous,the distribution of anomalous monitoring stations of focal precursors is concentrated,and the anomaly ratio can reach 90%;but the spatial distribution of field precursors is sparse,and the anomaly ratio is about 45%~53%;the spatial distribution of remote precursors is sparser,the anomaly ratio is 25%.Usually,the beginning time is different,most of anomaly time of focal precursors is medium-term;most of anomaly time of moderately strong earthquakes field precursors is medium-short term,particularly short-term;most of anomaly time of strong earthquake′s field precursors is medium-term;and most of anomaly time of strong earthquake’s remote precursors is medium-term too.The anomaly patterns are different,most of medium-term anomalies of focal precursors and strong earthquake′s field precursors show the step-like rising tendency,and most are chemical observational items,the oil-gas wells show blowing.However,the anomalies of moderately strong earthquake′s field precursors are short-term,negative ones with obvious amplitude,and show pulse bound,high value rising within short time,step-like change,and the regularity of yearly variation is broken.The remote precursory characteristics of strong earthquakes are medium-term anomalies for few observational stations and observational items;the suddenly ump phenomenon of several observational items exists during impending earthquake,the oil-gas wells also show blowing.更多还原