陕西中部地区近年来重力和应变场变化特征研究

RECENT VARIATION CHARACTERISTICS OF GRAVITY AND STRAIN FIELDS WITHIN MIDDLE REGION OF SHAANXI

基于2001—2005年陕西中部地区重力观测资料和GPS区域应变资料，研究了其重力场和应变场的分布与变化特征，结果表明：1）近年来陕西中部重力场和应变场的变化整体趋势一致，都是西升东降，南升北降；2）在西侧靠近鄂尔多斯西南弧形断裂带处，重力和最大剪应变均为正高值，并呈压缩状态；而中东部局部地区尤其是口镇．关山断裂带附近，重力为负值，最大剪应变呈高值状态，并受面拉张的作用与影响。

The recent（from 2001 to 2005） gravity and local GPS strain data in the middle region of Shaanxi are analysed. These data show that：1 ）both gravity and strain fields were coincidently rising in the west and the south, dropping in the east and the north;2）the gravity and maximal shear strain values along the arcuate fault belt of south-western Ordos were high and positive, and controlled by compress field, but the gravity value was negative and the maximum shear strain value was high in the middle-eastern area, especially, near the Kouzhen-Guanshan faults, where it was controlled by extensional plane strain field.