Determination of Geospatial Changes of the Barnes Ice Cap Using Eo Data

The determination of spatial changes in the arctic regions contributes to the understanding and quantification of spatio-temporal phenomena occurring in the polar environments and ecosystems. This paper presents the applicability of air and spaceborne earth observation data in the estimation of planimetric and elevation changes of the Barnes ice cap, located on Baffin Island, Nunavut in Northern Canada. Historic aerial photography, Landsat 7 imagery, NASA airborne LiDAR data and ICESat satellite LiDAR data were used to generate time series data consisting of orthoimages, DEM and terrain profiles. Indicative planimetric changes of the boundary edge of the ice cap were determined at sampled locations based on the available 1958 aerial ortho-images and the 20002002 Landsat 7 satellite ortho-image. These preliminary results indicate that the ice cap edge has retreated with an average rate of about 3-15m/yr during for the last 40 years. The elevation changes of the ice cap were estimated at the terrain profiles of the ICESat and NASA LiDAR elevation points, respectively using as reference 1958 photogrammetrically and contour generated DEMs. The comparison of the temporal terrain profiles indicates that the ice cap elevations have been lowered mostly at the sides of the ice cap and at the lower elevations, where the dropping average rate of the ice elevations is reaching approximately the 1m/yr during the last 40 years. The approaches for the determination of the planimetric and elevation changes are discussed and results are presented.