Present-day mass redistribution increases the total ocean mass and, on average, causes the ocean bottom to subside elastically. Therefore, barystatic sea level rise is larger than the resulting global mean geocentric sea level rise, observed by satellite altimetry and GPS-corrected tide gauges. We use realistic estimates of mass redistribution from ice mass loss and land water storage to quantify the resulting ocean bottom deformation and its effect on global and regional ocean volume change estimates.

A new model of glacial isostatic adjustment used in conjunction with GRACE satellite data suggests that ice loss from Antarctica is contributing 0.19 millimetres per year to global mean sea level, which is substantially less than previous GRACE-based estimates.