Global digital plate model PB2002_CASM and 1°×1° grid velocity field construction

Based on approximately 15,000 global station coordinates and velocity values, the plate model PB2002_CASM was constructed using actual measured velocity field analysis and supervised clustering analysis based on global PB2002 plate boundary divisions. For plates with more stations, mathematical interpolation algorithms were applied to calculate grid velocity values, including inverse distance weighting, Euler vector method, finite element interpolation method, least squares configuration method, kriging interpolation method, and linear interpolation based on triangulation. For plates with sparse or missing stations, such as in the ocean, singular spectrum analysis was used to extract trend components and obtain station motion speeds, and the PB2002_CASM plate motion model was used to calculate grid velocity values. There are a total of 61,560 1°×1° grids within the global longitude range of -179° to 180° and latitude range of -85° to 85°, which were mathematically interpolated to form 20,071 grid points. The PB2002_CASM plate motion model was used to calculate the velocity of 40,624 1°×1° grid points. The accuracy of the calculated velocity was validated, with a deviation within 1mm, achieving 82% and 89% accuracy in the E and N directions, respectively.