渭河盆地地形变观测结果分析  

Analysis of Weihe Basin′s Crustal Deformation Observations

作　　者：高好林[1] 丁晓光[1] 赵韬[1] 苏利娜[1] 古云鹤[1] 关昕[1] 张永奇[1] 

机构地区：[1]陕西省地震局,陕西西安710068

出　　处：《地震工程学报》2014年第2期292-300,共9页China Earthquake Engineering Journal

基　　金：地震行业专项(201208009-13)

摘　　要：在对渭河盆地GPS观测资料、流动重力和跨断层形变观测资料精细处理的基础上绘制了相应的时空变化图件,并对其进行了综合分析。结果表明:①陇县—岐山—周至—户县一线既是面应变压缩区,又是重力变化梯度带,还是布格重力异常梯度带,说明这一区域应力场异常变化与深部构造有关。②穿越该区域的陇县—岐山—马召断裂2010年以来断层活动表现为挤压变形特征,逆继承性构造运动显著。③在面应变率压缩区,地壳介质密度增加,重力场呈正向变化,断裂活动表现为挤压变形特征;反之则相反。④岐山-马召断裂2004年7月以后的两次逆继承性构造运动可能是甘肃迭部4.9和岷县6.6地震孕育发生过程中的远场效应。We selected the gps data since we have the GPS mobile observation network in Shaanxi province, and compared with the mobile gravity and cross-fault deformation observation data, we are aimed to investigate the variation of Weihe basin topography changes and their relationships. With the data of GPS mobile observation network in Shaanxi province during 2001--2010 and 2001--2012, the high-precision horizontal velocity field of Weihe basin processed by the software of GAMIT / GLOBK was obtained. The regional background strain characteristic parameters were calculated according to the velocity and strain theory by least squares collocation method. We have used the software,which is updated by China Institute of Seismology,to process the mobile gravity data of Guanzhong area,we also use some points nearby Weinan to do adjustment calculation to be stable. We have used the cross-fault deformation observation data,which is observed by high preci sion balance level NI002,to do the feet long correction. Based on fine processing on GPS observation data, mobile gravity and cross-fault deforma- tion observation data in Weihe basin, temporal and spatial variation maps are drawn correspond- ingly and further analyzed comprehensively combined with related deep detecting data and other research results. Results are shown mainly in 5 aspects as follows： @ Longxian--Qishan-- Zhouzhi--Huxian area is a surface strain compressed zone, a gravity change gradient belt and a Bouguer gravity anomaly gradient belt, which indicates that the abnormal changes in stress field in the area is related to the deep tectonics. The Moho mutants to uplift over the Erdos block and the high-speed substances in the upper mantle intrude into the lower crust is one of the deep tec- tonic backgrounds of moderate and strong earthquakes in the region. （~） Longxian--Qishan-- Mazhao fault, passing through the above mentioned area, is of significant inverse tectonic move- ment with fault movement characterized in extrusion deformation since 2010. What s

关 键 词：渭河盆地 地形变 GPS应变场 重力场变化 布格重力异常 跨断层形变 

分 类 号：P315.725[天文地球—地震学]