Abstract
An improved topography of the bed beneath the Antarctic Ice Sheet would further many scientific disciplines, including, ice sheet modelling, geoid interpretation, magnetic anomaly mapping, tectonic interpretation, ice core interpretation, oceanography, global isostasy and sea level prediction. Under the banner of BEDMAP and within the SCAR/GLOCHANT framework we present the most comprehensive compilation of ice thickness measurements over the Antarctic ice sheet to date. This compilation includes over 1 million data points contributed from ten nations in almost 100 expeditions carried out during the last fifty years. Although some areas, notably parts of central East Antarctica, still have only limited coverage, the number of data points in BEDMAP is two orders of magnitude greater than the only comparable compilation, the SPRI Folio 'The Bedrock Surface of Antarctica' published in 1983. The main application of this database is the determination gridded topographies describing both ice thickness and bed elevation for Antarctica. Utilising geographic information systems (GIS) technology we will include many types of data into a single determination of bed elevation. Data which will be incorporated include rock outcrop polygons, map/survey data including coastlines and other physiographic features, coastal bathymetry, ERS-1 satellite altimetry and airborne and oversnow altimetry. We will discuss the present status of the project, geographic coverage of the data, and future plans for the production of a hierarchy of gridded topographies and other parameters that will be of value to ice sheet modellers.