滇西地区GPS时间序列中陆地水载荷形变干扰的GRACE分辨与剔除  

Identification and elimination of non-tectonic crustal deformation caused by land water from GPS time series in the western Yunnan province based on GRACE observations

作　　者：盛传贞[1] 甘卫军[1,2] 梁诗明[1] 陈为涛[2] 肖根如[3] 

机构地区：[1]中国地震局地质研究所.地震动力学国家重点实验室,北京100029 [2]中国地震局地壳运动监测工程研究中心,北京100830 [3]东华理工大学,南昌344000

出　　处：《地球物理学报》2014年第1期42-52,共11页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41174082;41274018)资助

摘　　要：利用"中国大陆构造环境监测网络"在云南西部地区的13个连续GPS观测站和法国空间大地测量研究组Space Geodesy Research Group)的GRACE时变重力场资料,定量分析了该区域陆地水载荷所产生的非构造形变的量值和变化特点,探讨了利用GRACE分辨和剔除GPS观测中陆地水负荷所引起的非构造形变干扰的依据和模型.结果表明:滇西地区GPS坐标变化时间序列的垂向分量中,普遍包含有明显的年周期非构造形变波动,高值可达12mm,其中约42%源于陆地水迁徙变化所引起的负荷形变;通过主成份分析方法所获取的区域GPS共模误差与GRACE陆地水载荷形变序列的相关性高达0.87,若以GRACE扣除陆地水负荷形变,则滇西地区GPS网共模误差可消除约64%,且物理机制明确.然而,由于目前的GRACE只能有效分辨大约400km范围内陆地水载荷的整体变化,所以对于各GPS站点更加局部化的陆地水负荷非构造形变干扰,尚无法进行有效分辨.Based on the data of 13 continuous GPS stations in the western Yunnan province, China, from Crustal Movement Observation Network of China （CMONOC） and the GRACE time-varying gravity field data from Space Geodesy Research Group （GRGS）, France, we analyzed the magnitude and characteristics of the non-tectonic crustal deformation variation induced by land water migration in western Yunnan, and discussed the theoretical foundation and model for eliminating the non-tectonic deformation from GPS time series. The result shows that the non-tectonic crustal deformation fluctuation from GPS time series is significant in this area, with the maximum as large as 12ram, and about 42% of the fluctuation is from the crustal deformation induced by land water migration. By using the method of Principal Component Analysis （PCA）, we got the common mode error （CME） of the GPS network, which correlated with the GRACE land water loading deformation with a coefficient of about 0.87. When the land water loading deformation is used to correct the GPS error, the root mean square （RMS） of GPS common mode error will reduce by 64%. Therefore, a significant part of GPS common mode error in this area can be eliminated explicitly based on the GRACE time-varying gravity field. However, since GRACE can only effectively detect the overall land water loading deformation with a scope of 400km now, more detailed and specific non-tectonic deformation of individual GPS station is still out of the reach of GRACE.

关 键 词：滇西地区 陆地水载荷形变 GPS时间序列 非构造形变 

分 类 号：P228[天文地球—大地测量学与测量工程]