地壳结构对GRACE估算中国大陆地表垂直负荷形变的影响  

Effects of Crustal Structure for Estimation of Vertical Load Deformation on the Solid Earth Using GRACE in China Mainland

作　　者：贾路路[1,2] 相龙伟[2,3] 汪汉胜[2] 

机构地区：[1]地壳运动监测工程研究中心,北京100036 [2]中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室,湖北武汉430077 [3]中国科学院大学,北京100049

出　　处：《地球科学进展》2014年第7期828-834,共7页Advances in Earth Science

基　　金：国家自然科学基金项目"联合GRACE和卫星测高分离南极GIA和冰质量平衡的研究"(编号:41204013);地壳工程中心主任基金项目(2013)"联合卫星重力和GPS研究中国大陆地表质量驱动的周年垂直形变"资助

摘　　要：根据重力卫星GRACE(Gravity Recovery and Climate Experiment)估算固体地表垂直负荷形变时通常采用的PREM(Preliminary Reference Earth Model)地球模型不能较好地反映中国大陆特别是青藏高原巨厚的地壳结构。基于考虑中国大陆区域地壳结构的地球模型计算了新的负荷勒夫数,探讨了地壳结构差异对GRACE卫星RL05观测数据估算中国大陆地表垂直负荷形变的影响。结果表明,区域地壳结构差异对GRACE估算中国大陆地表负荷形变的影响较为明显,90阶垂直位移负荷勒夫数的相对差异接近11%;前90阶垂直负荷形变差异的极值出现在青藏高原东南部,最大相对差异达到10%左右,均方根相对差异为4%。建议利用GRACE卫星RL05数据估算中国大陆地表垂直负荷形变时,应该使用更加趋于真实的区域地壳结构替代PREM模型的相应部分。When the inversion of vertical load deformation on Earth＇ s surface using GRACE （ Gravity Recovery and Climate Experiment） data, the load Love numbers based on PREM （Preliminary Reference Earth Model） are commonly used. But the crustal structure under China mainland especially under Tibet Plateau is quite different from that given by PREM Earth model. New load Love numbers were calculated based on a modified Earth model which accounted for regional crustal structure in China mainland. And the effect of regional crustal structure in China mainland for estimation of vertical load deformation on Earth＇ s surface using GRACE RL05 data was investigated in this paper. It is found that the effect of crustal difference is very prominent. The relative difference of load Love numbers for vertical deformation can reach about ! 1% at degree 90. The extreme value of difference in vertical load deformation below 90 degree of spherical harmonic coefficients located at the southeastern Tibet Plateau and the maximum relative difference reaches 10%. The relative difference of the root mean square is about 4%. It is suggesting that an Earth model with a more realistic crustal structue instead of PREM should be used for the estimation of vertical load deformation in China mainland espacially in Tibet Plateau.

关 键 词：卫星重力 地表质量负荷 垂直形变 区域地壳结构 中国大陆 

分 类 号：P312.1[天文地球—固体地球物理学]