Like a pumpkin, Earth is a bit wider around the equator than the meridian. Since the end of the last glaciations, postglacial rebound of Earth's crust has resulted in a net transfer of mass from the equatorial regions to high latitudes. This small mass transfer has been monitored for 25 years. This slight oblateness (by about 0.3%) results from axial rotation and large-scale mantle convection. But newest science findings suggest that since 1998, the mass transfer has changed direction.
Previous
All photos in this category