Fig. 6

Figure showing schematics of various geophysical processes related to sea-level changes. a Crustal loading underneath of ice sheets in the “near-field” or center of ice sheet increases and mantle material flows beyond the ice sheet to form a peripheral bulge in the “intermediate-field” during ice sheet advances. Sites far from the ice sheet regions, where direct loading effects due to the change in ice sheet geometry is negligible are called “far-field”. For these locations, changes in the geometry and magnitude of water load influence the change in RSL. b The opposite is true during the waning phase of global ice sheets. Crustal uplift and peripheral bulge collapse occur in the near- and intermediate-fields due to mantle flow. In the far-field, a sea-level high-stand results from ocean siphoning due to the combination of bulge collapse and mantle flow from beneath the newly-loaded ocean basins. Earth’s rotational axis shifts because of mass exchanges between ice sheets and oceans and the effect of this process on Earth’s moment of inertia which in turn alters the centrifugal force applied to the water within the ocean basins. Reduction or increase in ice sheet mass produces a corresponding fall or rise in near-field sea level due to the change in gravitational attraction of the ice sheet on the water in the ocean basin