Thanks for any clarification. Answer: There are a number of difference between the NAD83 and the WGS84 datum. One is the reference ellipsoid. The North American 1983 datum (NAD83) uses the Geodetic Reference System (GRS80) ellipsoid while the World Geodetic System of 1984 (WGS84) uses the WGS 84 ellipsoid.What is the difference between NAD83 and NAD83 (CSRS)?
NAD83 (CSRS) represents a dynamic 3D realization of NAD83 (Original). Canada and the U.S. collaborated to redefine NAD83 in relation to the ITRF through a seven-parameter transformation using VLBI stations common to both systems.What is the difference between AD83 and WGS84?
The North American 1983 datum (NAD83) uses the Geodetic Reference System (GRS80) ellipsoid while the World Geodetic System of 1984 (WGS84) uses the WGS 84 ellipsoid. The dimensions of these ellipsoids differ slightly. For more information, refer to Projection basics the GIS professional needs to know.How do you align NAD83 (CSRS) to the North American Plate?
We keep NAD83 (CSRS) aligned to the North American plate using the NNR-NUVEL-1A estimate of plate motion. Since 1990, the most accurate and stable reference frames available are the successive versions of the ITRF produced by the International Earth Rotation and Reference Systems Service (IERS).