Glacial rebound and sea-level change around Greenland since the Last Glacial Maximum

Kevin Fleming, GeoForschungsZentrum, Potsdam, Germany
Prague, Sep 15, 2004

This seminar will introduce various aspects of the sea-level and glacial history of Greenland following the Last Glacial Maximum. A general description of the available sea-level indicator data will be presented, followed by a discussion dealing with efforts to produce a first-order model of the Greenland Ice Sheet (GIS). This made use of a gravitationally-self-consistent glacial-isostatic adjustment (GIA) model that incorporates realistic temporal and spatial changes in the GIS with a viscoelastic earth model. The contribution to past sea-level change around Greenland due to ice-load changes outside of that region has been considerable (10's of meters), and still contributes a rise of several mm yr-1 today. The isostatic contribution to relative sea level around Greenland from changes in the GIS is found by iteratively perturbing preliminary ice models with different LGM extents and deglaciation starting times (18 and 14 ka 14C BP), in order to minimise the misfit between predictions and observations of sea-level change. The resulting model contributes 3.1 and 1.9 m water-equivalent of additional ice relative to present-day ice volumes at the LGM and Younger Dryas, respectively. The GIS in most areas did not expand far onto the continental shelf, exceptions being southern-most Southwest Greenland and northern East Greenland, as well as at the coalescence of the Northwest Greenland and Innuitian Ice Sheets. A deglaciation starting time of 14 ka 14C BP is found to provide better results. Changes in ice thickness since the LGM were >500 m along the present-day outer coast and >1500 m along some parts of the present-day ice margin.

Last edited Oct 14, 2004