【摘要】 本文对1970年以来西宁盆地及邻近区域的中小震目录运用分时段累计频度、b值曲线、时间窗滑移等方法,对其监测能力的逐年变化情况进行了分析研究,并给出了不同时段的最小完整震级和最小可能完整性震级随时间变化的曲线.结果表明,本研究区域的地震监测能力逐年提高,由最初的ML2.3提升到目前的ML1.5.同时表明,在数次周边1000 km范围内的7级以上大震前,本区域的ML2~3明显增多,这一现象表明西宁盆地及邻近区域的小震活动特征具有一定的前兆指示意义.空间b值表明:西宁盆地内部一直处于较高b值的状态,而其外围尤其是北部区域处于低b值状态,值得持续关注.更多还原

【Abstract】 According the small and medium-sized earthquake catalog since 1970 in Xining basin and its adjacent area,we using period of time the cumulative frequency,b value curve,time sliding window method to research the monitoring ability, then give different period integrity minimum magnitude curve with time change. Result shows that the earthquake monitoring ability increase year by year,from the original ML2. 3 change to the current level ML1. 5. It also shows that before several times M ≥7 earthquake within the scope of 1000 km, the ML2 ~ 3 earthquake level increased significantly in research region. This phenomenon shows that the small earthquake activity characteristics in Xining basin and its adjacent area has a certain precursor instruction significance before some big earthquakes. Space b values indicate that internal Xining basin has been in the condition of high b value,but northern area and the periphery in a state of low b value,it worthy of sustained attention.更多还原