The geometry of sea-level change across a mid-Pliocene glacial cycle

• Main Authors: King, Meghan E., Creveling, Jessica R., Mitrovica, Jerry X.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2024
• Subjects: article; Verlagsveröffentlichung; East Antarctica; West Antarctica; Prydz Bay; Greenland; New Zealand; Antarc*; Antarctica; Ice Sheet
• Online Access: https://doi.org/10.5194/egusphere-2024-344; https://noa.gwlb.de/receive/cop_mods_00071842; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00070094/egusphere-2024-344.pdf; https://egusphere.copernicus.org/preprints/2024/egusphere-2024-344/egusphere-2024-344.pdf

Predictions for future sea-level change and ice sheet stability rely on accurate reconstructions of sea level during past warm intervals, such as the mid-Pliocene Warm Period (MPWP; 3.264 – 3.025 Ma). The magnitude of MPWP glacial cycles, and the relative contribution of meltwater sources, remains uncertain. We explore this issue by modeling glacial isostatic adjustment processes for a wide range of possible MPWP ice sheet melt zones, including North America, Greenland, Eurasia, West Antarctica, and the Wilkes Basin, Aurora Basin, and Prydz Bay Embayment in East Antarctica. As a case study, we use a series of ice histories together with a suite of viscoelastic Earth models to predict global changes in sea level from the Marine Isotope Stage (MIS) M2 glacial to the MIS KM3 interglacial. Our results indicate that, of the locations with stratigraphic constraints on Pliocene glacial–interglacial sea level amplitude, local sea-level (LSL) rise at Whanganui Basin, New Zealand, will be lower than the associated global mean sea level (GMSL) contribution from individual ice sheets by an average of ~20 %. In contrast, LSL rise at Enewetak Atoll is systematically larger than GMSL by 10 %. While no single observation (field site) can provide a unique constraint on the sources of ice melt during this period, combinations of observations have the potential to yield a stronger constraint on GMSL and to narrow the list of possible sources.