Measurement of the equivalence principle violating (EPV) quadrupole and other multipole moments of Earth in a space test of the equivalence principle (STEP) can reveal features of the new force's coupling strength to matter which are not obtainable from measurements of the free fall rate differences among various materials `dropped' in that future experiment. The Earth's EPV force field may include a dipole moment due to asymmetric distribution of the continents, and a quadrupole moment which differs from that of gravity due to the Earth's core-mantle compositional difference. Although the near-isostacy condition of the Earth crust substantially suppresses the crust's contributions to the higher gravity multipole moments of our planet, this will not necessarily be the case for the moments of any EPV force field detected by a STEP mission.