A Research On Present Horizontal And Vertical Crustal Movement In Guanzhong Area Based On GPS And Leveling Across Fault

The Guanzhong area and its adjacent regions are located in south of the Erdos block and are important deformation and strong-earthquake active zones. GPS and leveling across fault applied in the research of extent crustal movement can get exact spatial and temporal information, and it is possible to get the horizontal and vertical crustal movement field within short-term and check the existed geology model. Based on the formers' research results and research experience extensively, and combining Guanzhong area geological conformation background and earthquake characteristics, the horizontal and vertical crustal movement of the region have been analyzed using GPS and leveling across fault datas, its characteristics are listed:(1) Relative to Yulin site(D058), from 2001 to 2002, the motion velocity in Guanzhong area and its adjacent zones are characterized by distinct SE-directional stripped variation, and seem to show an incontinuous anticlockwise rotation; from 2002 to 2004, the motion velocity in Guanzhong area and its adjacent zones are characterized by distinct NE-directional stripped variation, and also seem to show an incontinuous anticlockwise rotation; from 2004 to 2005, the motion velocity in Guanzhong area and its adjacent zones are characterized by appear disparted-block characteristics, and not seem to take holistic rotation discontinuously.(2)Relative to Binxian site, there is a left-lateral shear belt on both sides of Binxian-Xi'an-Lantian zone in the central Guanzhong area, and its northern area has a better corresponding relationship with the dense zone of small earthquakes in Tongchuan-Jingyang-Lintong-Weinan. Perhaps the left-lateral shear belt mainly control the earthquake activity in the central Guanzhong area. In the whole, movement of east spots is disciplinary and movement rate is large, and is about 6-7 mm/a; movement of middle and west spots is not disciplinary, and movement rate is small. (3) From Mar.2001 to Mar.2003, the charts of vertical movement isolines present disciplinarian, and all behave a vertical movement of subsiding-ascending- subsiding from northwest to southeast(or from southeast to northwest).(4) The distributing of long interval movement is gently, the entire vertical movement direction is east-high, west-low, and as the interval is larger, the vertical movement rate is smaller.