Towards an ITRF2020 plate motion model

For various geodetic and geophysical applications, users need to have access to a Plate Motion Model (PMM) that is consistent with the ITRF2020 frame. The aim of this paper is to evaluate different possible approaches for determining a PMM from the horizontal velocities of a subset of the ITRF2020 sites away from plate boundaries, Glacial Isostatic Adjustment regions and other deformation zones. Compared with the ITRF2014-PMM, we assess in particular the performance of a PMM based on ITRF2020 velocity field, which contains more sites in some large tectonic plates, such as North and South Americas, Australia, and to some extent Antarctica. Using a global inversion of all plates all together, with full variance-covariance information, the angular velocities of these plates are expected to be improved in the ITRF2020 plate motion model. We also investigate the impact of subtracting GIA horizontal velocity predictions of different models before adjusting for angular plate velocities. Early results will be presented and discussed.