基于合成速率法的青藏块体东北缘断裂活动分析

The Fracture Activity Analysis of the Northeast Margin of Qinghai-Tibetan Block Based on the Synthetic Rate Method

摘要:

基于合成速率法、趋势累积率法与跨断层资料等的结合，从时空的不同角度分析了青藏块体东北缘主要断裂应变积累的运动特征。结果显示：①2010~2016年，祁连山断裂带呈微弱拉张的运动态势，海原断裂带由张转压，六盘山断裂带在门源地震前显示张性运动，震后发生转折；②长期来看，基于趋势累积率D_c的计算结果显示了祁连山断裂带中、西段累积应变略高于东段，从量值上看整个青藏块体东北缘D_c高值区位于六盘山断裂带附近。

Abstract:

Based on the combination of the synthetic rate,the trend accumulation rate method and the cross-fault data,this paper analyzes the movement characteristics of the main fault strain accumulation in the northeastern margin of the Qinghai-Tibetan Block from different angles of time and space. The result shows that:(1)In the short term,the movement situation of the Qilianshan fault zone is weak. The movement characteristics of the Haiyuan fault is from extension to extrusion. Before the Menyuan earthquake,the movement characteristics of the Liupanshan fault is extension,and has a turning point.(2)In the long run,the calculation results based on trend accumulation rate show that the cumulative strain of the middle west of Qilianshan Fault zone is slightly higher than the East. From the numerical value about the northeast margin of Qinghai-Tibetan Block,the D_c high value region is near the Liupanshan faults.