Balancing the last glacial maximum (LGM) sea-level budget

Abstract Estimates of post- Last Glacial Maximum(LGM) sea-level riseare not balanced by the estimated amount of ice melted since the LGM. We quantify this “missing ice” by reviewing the possible contributions from each of the major ice sheets. This “missing ice” amounts to 18.1 ± 9.6 m of global sea-level rise. Ocean expansion accounts for 2.4 ± 0.3 m of this discrepancy while groundwater could contribute a maximum of another 1.4 m to this offset. After accounting for these two potential contributors to the sea-levelbudget, the shortfall of 15.6 ± 9.6m suggests that either a large reservoir of water (e.g. a missing LGM ice sheet) has yet to be discovered or current estimates of one or more of the known LGM ice sheetsare too small. Included within this latter possibility are potential inadequacies of current models of glacial isostatic adjustment.