北京及邻近地区中等以上地震地下流体异常识别与特征研究

Study on recognition of fluid anomaly and its characteristics for moderately strong earthquakes in Beijing region and its adjacent area

系统分析了北京及其邻区多年积累的震例资料,提出该区的地下流体异常分为趋势上升型中期异常、转折型中短期异常、突发型短期异常和短临异常等类型。运用“同一化”思路、从属函数、剩余曲线及原始曲线均方差等异常判定方法,提取了中等以上地震,特别是5级以上地震的中、短、临异常实例。通过对流体异常特征的统计分析,给出了北京及邻近地区的中期、中短期、短期和短临异常的时间分布特征,并对地震前各阶段异常的超前时间进行了总结,该时间可作为发震时间的预测指标。在实际应用中可为该区的震情判定提供依据。

This paper systematically analyzed the data of earthquake cases in Beijing and its adjacent area accumulated for many years, and point out that fluid anomaly can be divided by medium-term anomaly, medium-short term anomaly, short-term anomaly and short-imminent anomaly. Using ＂identity＂ idea and anomaly criterion of slave function, remaincurve and original-curve deviation etc, a set of medium-term, short-term and imminentterm anomaly of the moderately strong earthquakes, especially those with intensity ≥V, above magnitude 5 earthquakes are extracted. Through statistics and analysis of fluid anomaly characteristics, this paper obtained the time distribution characteristics of fluid anomaly of the moderately strong earthquakes, especially those with intensity ≥ V, earthquakes in Beijing and its adjacent area, and summarized the leading time of each phases anomaly before the earthquakes, which can be regarded as index of occurrence time of earthquakes. It can provide reference for earthquake monitoring in this area.