Calibrated relative sea levels constrain isostatic adjustment and ice history in northwest Greenland
Relative Sea Levels (RSLs) derived primarily from marine bivalves near Petermann Glacier, NW Greenland, constrain past regional ice-mass changes through glacial isostatic adjustment (GIA) modeling. Oxygen isotopes measured on bivalves corrected for shell-depth habitat and document changing meltwater input. Rapid RSL fall of up to 62 m/kyr indicates ice loss at or prior to ∼9 ka. Transition to an RSL stillstand starting at ∼6 ka reflects renewed ice-mass loading followed by further mass loss over the past few millennia. GIA simulations of rapid early RSL fall suggest a low regional upper-mantle viscosity. Early loss of grounded ice tracks atmospheric warming and pre-dates the eventual collapse of Petermann Glacier's floating ice tongue near ∼7 ka, suggesting grounding zone stabilization during early phases of deglaciation. We hypothesize mid-Holocene regrowth of regional ice caps in response to cooling and increased precipitation, following loss of the floating shelf ice. Remnants of these ice caps remain present but are now melting.
Citation Information
Publication Year | 2022 |
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Title | Calibrated relative sea levels constrain isostatic adjustment and ice history in northwest Greenland |
DOI | 10.1016/j.quascirev.2022.107700 |
Authors | Anna Glueder, Alan Mix, Glenn A. Milne, Brendan Reilly, Jorie Clark, Martin Jakobsson, Larry Mayer, Stewart Fallon, John R. Southon, June Padman, Andrew Ross, Thomas M. Cronin, Jennifer McKay |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Quaternary Science Reviews |
Index ID | 70251409 |
Record Source | USGS Publications Warehouse |
USGS Organization | Eastern Geology and Paleoclimate Science Center; Florence Bascom Geoscience Center |