Tidewater glacier fluctuations in central East Greenland coastal and fjord regions (1980s-2005)

Summer 2000/01 ASTER and Landsat 7 scenes and semi-automated digitization were used to compile a glacier inventory for local glaciers of the Geikie Plateau region, central East Greenland. Of the 332 glaciers (41 591km²), 120 are tidewater-terminating and drain 90% of the glacierized area. Differencing the 2000/01 tidewater margins from the 1980s GEUS map database ice polygons (113 glaciers) and from 2004/05 ASTER tidewater margins (78 glaciers) shows a cumulative tidewater terminus width decrease from 196km to 183km between the 1980s and 2000s, with a corresponding areal loss of -31 km²and an effective length change of -14.3 km. Between 2000/01 and 2004/05, areal loss was 26 km². Average margin retreat rate increased two- to threefold, from 1.7-2.1km² a^-1 (1980s- 2000) to 3.9-5.7km² a^-1 (2000-05). Advances are negligible, apart from two surges, of which one was previously undetected. Coastal, 'outer' fjord-terminating, glaciers have two to three times larger areal and effective length retreat rates than 'inner' fjord-terminating glaciers. We investigate possible causes and hypothesize that, in addition to ocean temperature and sea ice, changes in sea fog may affect coastal-terminating more than inner fjord-terminating glaciers.