Accuracy of the International Terrestrial Reference Frame origin and Earth expansion

The International Terrestrial Reference Frame (ITRF) is a fundamental datum for high?precision orbit tracking, navigation, and global change monitoring. Accurately realizing and maintaining ITRF origin at the mean Earth system center of mass (CM) is critical to surface and spacecraft based geodetic measurements including those of sea level rise and its sources. Although ITRF combines data from satellite laser ranging (SLR), Very Long Baseline Interferometry (VLBI), Global Positioning System (GPS), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS), its origin is currently realized by the single technique of SLR. Consequently, it is difficult to independently evaluate the origin accuracy. Also, whether the solid Earth is expanding or shrinking has attracted persistent attention. The expansion rate, if any, has not been accurately determined before, due to insufficient data coverage on the Earth's surface and the presence of other geophysical processes. Here, we use multiple precise geodetic data sets and a simultaneous global estimation platform to determine that the ITRF2008 origin is consistent with the mean CM at the level of 0.5 mm yr?1, and the mean radius of the Earth is not changing to within 1? measurement uncertainty of 0.2 mm yr?1.

[1]  Meghan S. Miller,et al.  Present‐day motion of the Sierra Nevada block and some tectonic implications for the Basin and Range province, North American Cordillera , 2000 .

[2]  M. Tamisiea,et al.  Recent mass balance of polar ice sheets inferred from patterns of global sea-level change , 2001, Nature.

[3]  Michael B. Heflin,et al.  Seasonal and interannual global surface mass variations from multisatellite geodetic data , 2006 .

[4]  W. Farrell.  Deformation of the Earth by surface loads , 1972 .

[5]  Ichiro Fukumori,et al.  Assimilation of TOPEX/Poseidon altimeter data into a global ocean circulation model: How good are the results? , 1999 .

[6]  Michael B. Heflin,et al.  Simultaneous estimation of global present-day water transport and glacial isostatic adjustment , 2010 .

[7]  E. Ivins,et al.  Antarctic glacial isostatic adjustment: a new assessment , 2005, Antarctic Science.

[8]  George E. Williams,et al.  Geological constraints on the Precambrian history of Earth's rotation and the Moon's orbit , 2000 .

[9]  Kosuke Heki,et al.  The baseline length changes of circumpacific VLBI networks and their bearing on global tectonics , 1989 .

[10]  Xavier Collilieux,et al.  Global sea-level rise and its relation to the terrestrial reference frame , 2009 .

[11]  G. Blewitt,et al.  A New Global Mode of Earth Deformation: Seasonal Cycle Detected , 2001, Science.

[12]  W. Peltier.  GLOBAL GLACIAL ISOSTASY AND THE SURFACE OF THE ICE-AGE EARTH: The ICE-5G (VM2) Model and GRACE , 2004 .

[13]  Z. Altamimi,et al.  ITRF2008: an improved solution of the international terrestrial reference frame , 2011 .

[14]  M. Watkins,et al.  GRACE Measurements of Mass Variability in the Earth System , 2004, Science.

[15]  Pascal Willis,et al.  Terrestrial reference frame effects on global sea level rise determination from TOPEX/Poseidon altimetric data , 2004 .

[16]  S. W. Carey.  The expanding Earth , 1976 .

[17]  L. Vermeersen,et al.  A new class of stratified viscoelastic models by analytical techniques , 1997 .

[18]  Z. Altamimi,et al.  ITRF2005 : A new release of the International Terrestrial Reference Frame based on time series of station positions and Earth Orientation Parameters , 2007 .

[19]  Gary T. Mitchum,et al.  Monitoring the Stability of Satellite Altimeters with Tide Gauges , 1998 .

[20]  Maik Thomas,et al.  Simulation and observation of global ocean mass anomalies , 2007 .

[21]  Peter J. Clarke,et al.  Geocenter motions from GPS: A unified observation model , 2006 .

[22]  R. Müller,et al.  Global pulsations of intraplate magmatism through the Cenozoic , 2010 .