利用重力资料和GPS数据研究伽师及邻近地区地壳运动特征,首先对2005～2009年该区域流动重力观测资料进行平差计算,绘制出以1年为尺度的重力场变化的等值线图。分析表明,伽师及邻近地区近年来重力场变化相对活跃,且有一定的规律,最大重力异常值达到150×10-8 m.s-2。其次,利用2005～2009年该区域GPS数据在统一框架下进行重新解算,并利用理论计算得到该地区每年的面膨胀值。研究表明,该区域地壳面压缩、面膨胀交替出现,正负交界处往往是剪应变值增大的地区,即地震易孕育区域。最后探讨了重力与GPS(面膨胀)二者在地壳形变、地球动力之间的响应关系。研究表明,震前伽师及邻区重力值主要显示正变化,震后则呈现出大面积负值区域,说明压陷(面收缩)和向北扩张(面膨胀)作用交替进行,这与GPS计算出的面膨胀结果是一致的。

The paper studies the characteristics of crustal movement in Jiashi and its neighboring regions on the basis of gravity and GPS data． The adjustment calculation was done using the 2005 ～ 2009 gravity observation data flow and one-year gravity field variation scale images were drawn． The analysis reveals that the gravity field variations in the region is relatively active and follow certain patterns with the maximum cumulative gravity anomaly reaching 150 × 10 － 8m·s － 2 ． The paper then recalculates the GPS data of 2005 ～ 2009 in the region under a unified framework and obtains the annual surface expansion in the region by theoretical calculation． The result shows that the regional crustal surface compression and surface expansion have an alternating pattern，and the positive and negative junction is the increase area of shear strain，often the earthquake preparation area． Finally the paper discusses the correspondent relationship between gravity and GPS (surface expansion) in crustal deformation and geodynamics． The study shows that there are positive variations of gravity in Jiashi and its neighboring regions before a quake and negative ones in large areas after a quake． This can result from the alternation of indentation (surface contraction) and northward expansion ( surface expansion ) and is consistent with surface expansion by GPS calculation．

新疆维吾尔自治区科学研究与技术开发攻关计划(200741121); 地震科技星火计划项目(XH1030); 地震科学联合基金(A08056); 新疆天山中段强震危险区跟踪专题、新疆地震科学基金(201117、201116)联合资助