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

• Published in: Quaternary science reviews 2019-02, Vol.205, p.143-153
• Main Authors: Simms, Alexander R., Lisiecki, Lorraine, Gebbie, Geoffrey, Whitehouse, Pippa L., Clark, Jordan F.
• Format: Article
• Language: English
• Subjects: Antarctica; Eustatic; Lowstand; Pleistocene; Sea level
• ISSN: 0277-3791; 1873-457X
• DOI: 10.1016/j.quascirev.2018.12.018

Estimates of post-Last Glacial Maximum (LGM) sea-level rise are 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-level budget, 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 sheets are too small. Included within this latter possibility are potential inadequacies of current models of glacial isostatic adjustment. •We quantify the amount of “missing ice” at the LGM.•The ocean-density component to sea-level rise since the LGM is 2.4 ± 0.3 m.•Groundwater contributed no more than 1.4 m to sea-level rise since the LGM.•These two components leave 15.6 ± 9.7 m of missing sources of sea-level rise since the LGM.