Abstract
The quantitative assessment of glacier changes as well as improved modeling of climatechange impacts on glaciers requires digital vector outlines of individual glacier entities. Unfortunately, such a glacier inventory is still lacking in many remote but extensively glacierized regions such as the Canadian Arctic. Multispectral satellite data in combination with digital elevation models (DEMs) are
particularly useful for creating detailed glacier inventory data including topographic information for each entity. In this study, we extracted glacier outlines and a DEM using two adjacent Terra ASTER scenes acquired in August 2000 for a remote region on southern Baffin Island, Canada. Additionally, Little Ice Age (LIA) extents were digitized from trimlines and moraines visible on the ASTER scenes, and
Landsat MSS and TM scenes from the years 1975 and 1990 were used to assess changes in glacier length and area. Because automated delineation of glaciers is based on a band in the shortwave infrared, we have developed a new semi-automated glacier-mapping approach for the MSS sensor. Wrongly classified debris-covered glaciers, water bodies and attached snowfields were corrected manually for both ASTER
and MSS. Glacier drainage divides were manually digitized by combining visual interpretation with DEM information. In this first paper, we describe the applied methods for glacier mapping and the glaciological challenges encountered (e.g. data voids, snow cover, ice caps, tributaries), while the second paper reports the data analyses and the derived changes.
Svoboda, F