环鄂尔多斯断陷盆地现今地壳运动与构造环境特征的GPS研究

项目名称： 环鄂尔多斯断陷盆地现今地壳运动与构造环境特征的GPS研究

项目编号： No.41304019

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 赵斌

作者单位： 中国地震局地震研究所

项目金额： 25万元

中文摘要： 内部稳定的鄂尔多斯块体四周被依次形成的渭河断陷盆地、银川-吉兰泰断陷盆地、河套断陷盆地、山西地堑系及断裂所围限，其构造演化历史、形变模式、动力学背景一直是地学界争论的焦点。已有的大地测量与地震地质对该区域断层活动、地壳形变的研究结果之间差异显著。本项目拟对研究区域内1992年以来的大密度GPS监测资料，采用优化的地球物理模型和数据处理技术进行精化处理，获得自洽的高精度速度场；采用多种正反演方法，对控制鄂尔多斯块体周缘大地震的断裂带进行分段、系统研究，精确测定其滑动速率、拉张速率及闭锁状况等运动参量；结合地震地质、地球物理等资料深入探讨断层滑动速率GPS结果与地质结果的差异原因；在此基础上，试图从现今大陆变形动力学的视角探讨鄂尔多斯块体周缘地壳形变的构造背景及形变模式。本项目对新生代华北地区形变机理与大陆动力学研究均具有重要意义。

中文关键词： 鄂尔多斯块体；断陷盆地；滑动速率；GPS；

英文摘要： The Ordos block in itself has been very stable. In contrast, the margins of this stable block have been the site of active Cenozoic tectonics in northeastern China. The block has been surrounded by four rift systems: the Weihe graben to the south, Yinchuan rift basins to the west, the Hetao rift zone to the north, and the Shanxi graben to the east. Circum-Ordos rifts are characterized by extensional shear zones, expecting on the southwestern edge, which has been compressed by Tibet in the NE-NNE direction. Historic records show four M=8 and more than 30 M≥6 earthquakes in these rift zones. Extensive GPS measurements in the past two decades, along with newly constructed campaign sites of CMONOC (Crustal Movement Observation Network of China), provide unprecedented opportunities to studying detailed deformation of faults in this region. In our research, we will try to collect and reprocess more than 1000 GPS sites from 1992 up to now, using the latest geophysical correction models and final satellites orbits to obtain accuracy self-consistent GPS velocities. Then, fault slip rates and locking depths of the rift systems will be estimated using different deformation models, such as screw dislocation model, GPS velocity profiles model and rigid block model. Given that different simulation models may result in differe

英文关键词： Ordos block；rift system；slip rate；GPS；