Global plate motion models incorporating the velocity field of ITRF96

In this paper, incorporating the ITRF96 velocity field that is free of any tectonic plate model assumption, a new present-day plate motion model relat ive to the ITRF96 reference frame, called the ITRF96VEL, is determined. The total angular momentum of all tectonic plates with regards to the ITRF96VE L shows that the ITRF96 rotates in a right-handed sense relative to the no- net-rotation (NNR) reference frame at 0.164 degrees/m.yr. about 50.7 degree s S, 65.8 degrees E. This means that ITRF96 is not sufficiently concordant with the definition of the Conventional Terrestrial Reference System (CTRS) . In order to more properly compare plate motions from the ITRF96 velocity field with the NNR-NUVEL1A, another plate motion model relative to the NNR reference frame, called the NNR ITRF96VEL, is also established. The results indicate that the NNR-ITRF96VEL is quite consistent with the NNR-NUVEL1A. The consistency testifies to the reliability of the NNR-NUVEL1A, and shows the tectonic plate motions were steady over past millions of years.