Evidences of the expanding Earth from space-geodetic data over solid land and sea level rise in recent two decades  

作　　者：Shen Wenbin Shen Ziyu Sun Rong Barkin Yuri 

机构地区：[1]Department of Geophysics,School of Geodesy and Geomatics,Key Laboratory of Geospace Environment and Geodesy of Ministry of Education,Wuhan University [2]State Key Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan University [3]School of Physics,Huazhong University of Science and Technology [4]Sternberg Astronomical Institute,Moscow State University

出　　处：《Geodesy and Geodynamics》2015年第4期248-252,共5页大地测量与地球动力学（英文版）

基　　金：supported by National 973 Project China(2013CB733305,2013CB733301);National Natural Science Foundation of China(41174011,41429401,41210006,41128003,41021061)

摘　　要：According to the space-geodetic data recorded at globally distributed stations over solid land spanning a period of more than 20-years under the International Terrestrial Reference Frame 2008,our previous estimate of the average-weighted vertical variation of the Earth＇s solid surface suggests that the Earth＇s solid part is expanding at a rate of 0.24 ± 0.05 mm/a in recent two decades.In another aspect,the satellite altimetry observations spanning recent two decades demonstrate the sea level rise（SLR） rate 3.2 ± 0.4 mm/a,of which1.8 ± 0.5 mm/a is contributed by the ice melting over land.This study shows that the oceanic thermal expansion is 1.0 ± 0.1 mm/a due to the temperature increase in recent half century,which coincides with the estimate provided by previous authors.The SLR observation by altimetry is not balanced by the ice melting and thermal expansion,which is an open problem before this study.However,in this study we infer that the oceanic part of the Earth is expanding at a rate about 0.4 mm/a.Combining the expansion rates of land part and oceanic part,we conclude that the Earth is expanding at a rate of 0.35 ± 0.47 mm/a in recent two decades.If the Earth expands at this rate,then the altimetry-observed SLR can be well explained.According to the space-geodetic data recorded at globally distributed stations over solid land spanning a period of more than 20-years under the International Terrestrial Reference Frame 2008,our previous estimate of the average-weighted vertical variation of the Earth＇s solid surface suggests that the Earth＇s solid part is expanding at a rate of 0.24 ± 0.05 mm/a in recent two decades.In another aspect,the satellite altimetry observations spanning recent two decades demonstrate the sea level rise（SLR） rate 3.2 ± 0.4 mm/a,of which1.8 ± 0.5 mm/a is contributed by the ice melting over land.This study shows that the oceanic thermal expansion is 1.0 ± 0.1 mm/a due to the temperature increase in recent half century,which coincides with the estimate provided by previous authors.The SLR observation by altimetry is not balanced by the ice melting and thermal expansion,which is an open problem before this study.However,in this study we infer that the oceanic part of the Earth is expanding at a rate about 0.4 mm/a.Combining the expansion rates of land part and oceanic part,we conclude that the Earth is expanding at a rate of 0.35 ± 0.47 mm/a in recent two decades.If the Earth expands at this rate,then the altimetry-observed SLR can be well explained.

关 键 词：ITRF2008 coordinates Ice melting Thermal expansion Earth expansion Sea level rise （SLR）Space-geodetic data Velocities altimetry Earth＇s solid surface 

分 类 号：P228[天文地球—大地测量学与测量工程]