青藏块体东北缘地区断层形变研究

Research on Fault Deformation in Northeast Margin Area of Qinghai-Tibet Block

摘要:

根据青藏块体东北缘地区的跨断层流动水准测量资料,分别从断层形变异常的空间分布特征,不同断裂带上断层形变平均活动速率的分布和断层形变群体性异常在时间上的分布三个方面进行了统计、对比、分析和研究.结果显示,自2002年以来青藏块体东北缘地区的断层形变异常的主体区域逐步由西向东迁移,地震活动也具由西向东迁移的现象;断层平均活动速率也是东部区偏高.但是,断层形变群体异常在时间上的分布显示目前该区域断层形变异常活动的数量和强度均不十分显著,短期内发生强震的可能性不大.本文提出的方法及初步结论对该区域日常地震预测及震情跟踪工作有一定的参考价值.

Abstract:

Based on the data of leveling across faults in northeast margin area of Qinghai--Tibet block,the statistics, comparison, analysis and study are made on three aspects as follows： the spatial distribution of abnormal fault deformation, the average rate of fault movement in different belt, and the distribution of group abnormal fault deformation in time dimension. The results show that, since 2002, the principal region of fault deformation anomolies are transferred gradually from west to east in northeast margin area of Qinghai--Tibet block; the seismic activities are also similarly transferred from west to east; and the average rate of fault movement in the east part is higher than other parts of the research area. But the distribution of group abnormal fault deformation in time dimension shows that, at present, the anomalies are not distinct enough in magnitude and amount, thus, it＇s impossible having strong earthquake in this area in near future. The primary results and the study method presented in this paper have a reference value for daily work of earthquake prediction and seismic trending research.