川滇地区现今三维地壳运动特征  

Characteristics of Present-Day 3D Crustal Movement of Sichuan-Yunnan Region

作　　者：田晓[1] 占伟[1] 郑洪艳[1] 尹海权[1] TIAN Xiao;ZHAN Wei;ZHENG Hongyan;YIN Haiquan(The First Monitoring and Application Center,CEA,7 Naihuo Road,Tianjin 300180,China)

机构地区：[1]中国地震局第一监测中心,天津市300180

出　　处：《大地测量与地球动力学》2021年第7期739-746,共8页Journal of Geodesy and Geodynamics

基　　金：中国地震局震情跟踪(2019010227);中国地震局“三结合”课题(3JH-201901090)。

摘　　要：利用1999~2018年GPS观测资料和1974~2014年2期(1974~1984、2013~2014)精密水准资料研究川滇地区现今三维地壳运动特征。结果表明:1)水平运动以继承性运动为主,近年滇西南地区旋转明显减弱;汶川地震导致龙门山断裂带西侧及川滇菱形块体东边界构造应力重新调整,近年震后调整明显减弱,正在向震前状态恢复;2)垂直运动总体表现为差异性隆升运动,且川滇西北部的上升运动速率明显大于东南部;龙门山断裂带北部高原地区的隆升速率为3~4 mm/a,川西高原的隆升速率为1~3 mm/a,滇西北地区的隆升速率为1~2 mm/a,滇西南思茅-江西村地区的下降速率为2~3 mm/a,川滇其他地区的运动速率基本在-1~1 mm/a;3)主要活动断裂两侧基本均存在一定的垂直差异性运动,鲜水河和龙门山断裂带差异性运动明显,并且具有分段性;4)川滇地区水平运动和垂直运动在地质构造上具有较好的一致性,近期龙门山断裂带西侧高原的水平运动减缓,挤压变形减弱,可能预示该地区将逐渐进入新一轮的能量积累时期,需要持续关注。Using the GPS data of 1999-2018 and the precise leveling data of two periods in 1974 to 2014(1974-1984,2013-2014),we study the characteristics of present-day 3D crustal movement of Sichuan-Yunnan region.The results show that:1)The horizontal movements are mainly inherited activities,and the rotation of southwest Yunnan has weakened obviously in recent years.The stress fields in the western Longmenshan fault and the eastern boundary of Sichuan-Yunnan rhombic block have readjusted due to the Wenchuan earthquake;the adjustments have weakened obviously in recent years,which are recovering to the pre-earthquake state.2)The vertical movements exhibit a different uplifting on the whole,with the uplift rate in the northwest Sichuan-Yunnan obviously larger than that in the southeast.The uplift rate of the northern plateau of Longmenshan fault zone is 3-4 mm/a,the uplift rate of the plateau in the western Sichuan is 1-3 mm/a,the uplift rate of the northwest Yunnan is 1-2 mm/a,the subsidence rate of Simao and Jiangxi village in the southwest Yunnan is 2-3 mm/a,and the movement rate of other parts of Sichuan-Yunnan region is basically-1-1 mm/a.3)There are normally some vertical differential movements on both sides of the main active faults,especially Xianshuihe and Longmenshan faults,which have segmented characteristics.4)The horizontal movement and vertical movement in the Sichuan-Yunnan region show good consistency in geological structure.Recently,the horizontal movement of the plateau in the western Longmenshan fault has slowed down and the compression deformation has weakened.It may indicate that the region is gradually entering a new period of energy accumulation,which requires continuous attention.

关 键 词：川滇地区 GPS 水准 三维地壳运动 

分 类 号：P315[天文地球—地震学]