基于形变速率累加法研究北天山地区形变异常与孕震关系

RELATIONSHIP BETWEEN DEFORMATION ANOMALIES AND SEISMOGENESIS IN NORTH TIANSHAN MOUNTAINS BASED ON ACCUMULATION OF DEFORMATION RATE METHOD

利用北天山地区多期一等跨断层垂直形变观测资料和GNSS数据,采用“形变速率累加”异常识别方法进行处理,结合震例分析断层形变异常特征。结果表明,“形变速率累加”易于异常识别和提取,可直观的显示出连续异常点的快速上升和阶跃变化,在异常特征分析时具有一定的参考价值;异常时段以中短期为主,大部分异常信息出现在M_(S)≥6.0地震震中300 km范围内,从地震异常信息起始至发震过程分析,该方法可作为地震中期预测指标;GNSS三分量异常幅度N<E<U,均值为30.5 mm,异常速率为0.33 mm/d,该方法基本适用于GNSS形变资料的异常信息提取。

Based on the observation data and GNSS data of multi-stage vertical deformation across the first-order fault in North Tianshan Mountains,the anomaly characteristics of fault deformation were analyzed by the method of"deformation rate accumulation"anomaly recognition.The results show that the"deformation rate accumulation"is easy to identify and extract anomalies,and can directly show the rapid rise and step change of continuous anomalies,which has a certain reference value in the analysis of abnormal characteristics.Most of the anomaly information occurs in the epicenter of M_(S)≥6.0 within 300 km.From the beginning of the abnormal information to the analysis of the seismogenic process,this method can be used as a medium term prediction index of earthquakes.The anomaly amplitude of GNSS three components is N<E<U,with an average value of 30.5 mm and an anomaly rate of 0.33 mm/d.This method is basically suitable for the extraction of anomaly information from GNSS deformation data.