Fig. 4
From: A local lithospheric structure model for Vietnam derived from a high-resolution gravimetric geoid

a Geoid undulations by adding transformation from gravimetric quasigeoid to geoid, b residual geoid undulation by simple subtraction of low d/o from 2 to 9, and c residual geoid undulation by removing low d/o from 2 to 9 with a 1D-Gaussian function