The first complete glacier inventory for the whole of Greenland

Abstract

Glacier inventories provide important baseline information for the determination of wa- ter resources, glacier-specific changes in area and volume, climate change impacts, and the past, potential and future contribution of glaciers to sea-level rise. Though 5 heavily glacierized and thus highly relevant for all of the above points, such an inventory of all local glaciers and icecaps (GIC) was not available so far for Greenland. Here we present the details and results of our inventory, that has been compiled from more than 70 Landsat scenes mostly acquired between 1999 and 2002 using semi-automated multispectral mapping techniques. A digital elevation model (DEM) was used to derive 10 drainage divides from watershed analysis and topographic parameters for each glacier entity. We assigned to each entity one of three connectivity levels (CL0, CL1, CL2; i.e. no, weak, and strong connection) with the ice sheet to distinguish the local GIC from the ice sheet and its outlet glaciers and to serve the specific needs of different user communities. All GIC larger 0.05km2 include ∼20 300 entities (of which 900 are ma- 15 rine terminating), covering an area of 129983±4029km2, or 89273±2767km2 without the CL2 GIC. The latter is about 50% more than according to all previous estimates. Glaciers smaller 0.5km2 contribute only 1.5% to the total area but more than 50% (11 000) to the total number. In contrast, the 25 largest GIC (>500km2) contribute 28% to the total area, but only 0.1% to the total number. Most of the ice was located at ele- 20 vations around 1000 m, except in the eastern sector with elevation arround 1700 m. In addition, a strong dependence of the median elevation to the distance from the ocean was found, but only a weak dependence on aspect. All data will be made available in the Global Land Ice Measurement from Space (GLIMS) glacier database.