郝明,
秦姗兰,
王文萍
中国地震局第二监测中心, 西安 710054
基金项目: 国家重点研发计划（2017YFC1500102）和国家自然科学基金面上项目（41874117，51479163，41174083）资助
详细信息
作者简介: 崔笃信, 研究员, 主要研究方向为地壳形变、地震及地壳动力学.E-mail:cuiduxin@163.com
中图分类号: P315 收稿日期:2018-06-13
修回日期:2019-02-19
上线日期:2019-12-05
Inversion of fault dip-slip rate and locking depth in Central-Southern Shaanxi of China
CUI DuXin,HAO Ming,
QIN ShanLan,
WANG WenPing
The second monitoring and application Center, CEA, Xi'an 710054, China
MSC: P315
--> Received Date: 13 June 2018
Revised Date: 19 February 2019
Available Online: 05 December 2019
摘要
摘要:位于华北板块和扬子板块之间的陕西中南部由渭河盆地、秦岭造山带和汉中盆地构成，其新构造运动主要形式为山脉隆升、盆地断陷，因此以重复水准测量为手段的地壳垂直运动研究尤为重要.基于研究区1970年以来的多期精密水准测量数据，用GPS垂直运动速率约束的动态平差方法获得了区域垂直运动速度场.以此为基础，用倾滑位错模型、网格搜索方法反演了研究区主要断层倾滑速率和闭锁深度，结果显示：秦岭北缘断裂倾滑速率为2.25~4.53 mm·a-1，闭锁深度为7.7~10.0 km；华山山前断裂倾滑速率为2.35~2.71 mm·a-1；闭锁深度为2.8~5.0 km，反映了该断裂在华县大地震之后，可能还没有完全闭锁，发生大震的应变能积累条件不足；渭河盆地北缘断裂的倾滑动速率为2.0~2.5 mm·a-1，闭锁深度仅为3.0 km左右，说明该断裂以蠕滑运动为主；略阳断裂倾滑速率为3.02 mm·a-1，闭锁深度6.7 km，是陕南较活动的断裂.
关键词: 滑动速率/
闭锁深度/
精密水准测量/
渭河盆地/
秦岭
Abstract:Neotectonic movement of central and southern Shaanxi which is located between North China and Yangtze craton is represented by uplift of the Qinling Mountains and subsidence of the Weihe and Hanzhong basins. So the study of vertical crustal movement based on repeated leveling in this area is particularly important. We collected multi-period precise leveling data since 1970 s in the study area and obtained the vertical velocity field using the dynamic adjustment method with GPS vertical velocity constraints. Base on the velocity field we use grid search to inverse the fault dip-slip rates and locking depths. The result shows that the dip-slip rates of the northern margin of the Qinling fault are 2.25~4.35 mm·a-1 with the locking depths of 7.7~10.0 km. The dip-slip rates of the frontal fault of Huashan are 2.35~2.71 mm·a-1 with the locking depths of 2.8~5.0 km,which probably reveal that this fault is not locking completely. The dip-slip rates of the northern margin fault of the Weihe Basin are about 2.0~2.5 mm·a-1 with the locking depth of near 3.0 km,which means the fault is mainly creeping. The dip-slip rate for the east section of the Lueyang fault is 3.02 mm·a-1 with the locking depth of 6.7 km. This fault is a more active one in southern Shaanxi area.
Key words:Slipping rate/
Locking depth/
Precise leveling/
Wehe Basin/
Qinling Mountains
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