HR: 0800h
AN: G21B-0491 INVITED    [Abstracts]
TI: The Translation and Rotation With Which to Define the North American plate
AU: * Argus, D F
EM: Donald F. Argus@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Gordon, R G
AF: Department of Earth Science, Rice University, 6100 Main St., Houston, TX 77005, United States
AU: Peltier, W R
AF: Department of Physics, University of Toronto, 60 Saint George St., Toronto, ON M5S 1A7, Canada
AB: Estimates of site velocity in International Terrestrial Reference Frame 2005 [Altamimi et al. 2007] may, we propose, be transformed into a reference frame in which the North America plate is fixed using: Translation 1.9 millimeters per year toward 82.6S 121.8E Rotation 0.205 degrees per million years CCW about 0.3N 96.6E Resulting estimates of vertical rate of site motion are relative to (CE) the mass center of just solid Earth. Using four space techniques we simultaneously estimate the velocity of CE and the angular velocity of the plates assuming that places on plates not beneath or along the margins of the former ice sheets are moving horizontally negliglibly realtive to CE. Our estimate velocity of CE is likely nearer the true velocity of (CM) the mass center of Earth, oceans, and atmosphere than the velocity of CM in ITRF2005. The velocity of CM differs between ITRF2000 and ITRF2005 by nearly 2 millimeters per year, suggesting that the velocity of CM estimated using SLR observation of LAGEOS is poorly constrained. No phenomena is believed to sustain a velocity between CM and CE for many years, and the velocity of CE is constrained tightly by the 4 space techniques.
DE: 1229 Reference systems
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 8158 Plate motions: present and recent (3040)
SC: Geodesy [G]
MN: 2007 Fall Meeting