HR: 0800h
AN: G21B-0499    [Abstracts]
TI: The CORS network and improved understanding of the motion of stable North America
AU: * Sella, G
EM: giovanni.sella@noaa.gov
AF: NOAA-NGS, 1315 East-West Hwy., Silver Spring, MD 20910, United States
AU: Snay, R
EM: richard.snay@noaa.gov
AF: NOAA-NGS, 1315 East-West Hwy., Silver Spring, MD 20910, United States
AB: NOAA's National Geodetic Survey created in 1994 the Continuously Operating Reference Station (CORS) network in partnership with site operators of continuously operating GPS (CGPS) sites who were willing to share their data with the public. The network currently contains ~1,200 stations located mostly in the United States and is growing at ~200 stations per year. In North America most tectonic studies of deformation using GPS have concentrated on the active plate boundary of the western US and have related observed motions to the stable eastern part of the plate. Initially limited attention was paid to the robustness of the definition of the stable part of the plate as it was assumed to have little to no motion. As the resolution of GPS analysis has improved, increasing attention is now being focused on understanding the stable part of the plate. This new focus has made extensive use of CORS data as it contains most of the available CGPS data east of the Rocky Mountains. Perhaps the most dramatic conclusion of these studies has been that glacial isostatic adjustment is the largest motion affecting the stable part of the North American plate. Quantifying the extent and magnitude of this motion is critical to ensure that it does not bias geologic interpretations based on millimeter to sub-millimeter level observations. Understanding this crustal deformation assists NGS's in its mission to maintain and improve the accuracy and access to the National Spatial Reference System (NSRS). In turn NGS has been significantly improving the CORS infrastructure in collaboration with its partners as they rapidly establish new CGPS sites for real-time positioning and their desire for millimeter level accuracy. Although the legally binding reference frame for North America is the non-geocentric NAD83, the Plate Boundary Observatory's Stable North American Reference Frame (SNARF) provides a key step in its eventual replacement/update.
DE: 1211 Non-tectonic deformation
DE: 1229 Reference systems
DE: 1241 Satellite geodesy: technical issues (6994, 7969)
DE: 1243 Space geodetic surveys
SC: Geodesy [G]
MN: 2007 Fall Meeting