摘要
基于《中国震例》及其他相关的内部震例资料、研究报告及文献资料,对南北地震带地震前的定点形变异常整体特征进行了研究分析。结果表明：异常项数随震级升高而增大,但不同地震间差异较大。异常的最长持续时间和最大分布范围随震级增大而增大,但对于6.0-7.9级地震异常在震区附近出现＂围空＂现象。研究区内异常主要以趋势转折和破年变为主,其次为大幅突变、大幅波动、潮汐因子异常。各类异常的时空特征对地震的震级、时间和地点具有不同的指示作用。震前400天至200天的范围内异常数量会出现快速增加现象,对于6级以上地震还发现在震前200天以内出现异常数量的显著减少现象。另外,发现存在一些定点形变异常敏感台站,可能与区域构造及应力应变积累位置有关。
Based on Earthquake Cases in China,and other relevant internal materials,research report and published literature,this paper analyzes the whole characteristics of fix-point deformation anomalies before earthquakes of the North-South seismic belt.The results indicate that the numbers of anomalies increase with the raising of earthquake magnitude,but the discrepancies between different earthquakes are obvious.The longest duration and the upper boundary of distribution range of anomalies also increase with the earthquakes＇ magnitude,but a blank zone of anomalies appears around the seismic region of magnitude 6.0to 7.9earthquakes.The anomalies in the research area are mainly with the form of tendency reversing and annual variation changing,followed by sharp mutation,severe wobble and tide factor anomalies.The temporal and spatial characteristics of each anomaly form have different indicative function for the predicting of the magnitude,occurrence and location of earthquake.The numbers of anomalies rise rapidly 400 to 200days before the occurrence of earthquakes,and for earthquakes larger than magnitude 6significant decreases subsequently happen 200 days before the occurrence.Besides,some fixpoint deformation stations which are sensitive to precursor anomalies are found,and they may relate to the regional tectonics and accumulation regions of strain and stress.
出处
《地震》
CSCD
北大核心
2016年第4期76-88,共13页
Earthquake
基金
中国地震局地震预测研究所基本科研业务费专项(2014IES010106)
2015年度震情跟踪定向工作任务(2015010210)共同资助
