Introduction & Background
Introduction
Antarctica covers an area of some 13 million sq. km. In only around 0.4% of this area is the rock exposed (Fox and Cooper, 1994), the rest being covered by a permanent ice sheet that is in places more that 4500 m thick. The Antarctic Ice Sheet is a major control on world sea level and contains enough water to raise sea level by perhaps 65 m. In the last ten years mapping the topography of the surface of the Antarctic Ice Sheet has been advanced considerably through field surveying, satellite imagery and satellite altimetry. While mapping is, in places, still limited to scales smaller than 1: 10 000 000 digital maps are now available over the entire continent.

Mapping of the true surface of the continent beneath the ice sheet has not, however, kept pace. Whereas present and planned satellites can give an almost complete description of the surface of the ice sheet, neither present nor planned satellites will be able to look through the ice sheet. For the foreseeable future, we are restricted to terrestrial methods of measurement, primarily radar and seismic sounding. The high logistic costs of working in Antarctica have prevented any one nation from attempting to sound the entire continent. Rather, we have seen a largely uncoordinated and patchy coverage develop as many nations produced regional surveys to support their other scientific activities. We are now arriving in a position where no one individual or institute has a complete knowledge of where data have been collected and which areas remain to be visited. Furthermore, bed elevation collected in aid of other scientific disciplines are beginning to be lost as researchers leave the community, and in a short time this will become too difficult to recover.

The BEDMAP project was conceived as an attempt to rationalise the coverage of ice thickness measurements over Antarctica, collect the data together and produce a new topographic model of the bed of the Antarctic Ice Sheet, to provide a new basis for all aspects of Antarctic geoscience.

First BEDMAP Workshop
On 21 & 22nd of October 1996, a working group of 21 scientists from eight countries met in the Arundel House Hotel, Cambridge, UK, under the joint sponsorship of the European Ice Sheet Modelling Initiative (EISMINT) and the Scientific Committee on Antarctic Research (SCAR). They met to consider the desirability and feasibility of establishing an international database of ice thickness measurements over Antarctica and from this producing a new topographic model of the bed beneath the Antarctic Ice Sheet and the seabed of the surrounding continental shelf. The workshop achieved consensus on the following points:

  • Adequate topographic data is of fundamental importance to many scientific disciplines active in Antarctica, including, ice sheet modelling, geoid interpretation, magnetic anomaly mapping, tectonic interpretation, ice core interpretation, oceanography, global isostasy and sea level prediction

  • An outstanding step forward for Antarctic science would be achieved in many disciplines of Antarctic science by the production of a new topographic model for Antarctica

  • At present this can only be achieved by bringing together existing data from researchers across the world

  • We will endeavour to compile such a database of ice thickness measurements and then this will be compiled to give a variety of digital and map products of value to scientists

  • The work will be done under the banner of BEDMAP within the SCAR/GLOCHANT framework. All nations and researchers with appropriate data to contribute will be encouraged to join the BEDMAP Consortium

  • A steering committee will direct the project through its three phases, databasing, compilation of data and generation of products

  • The products of the BEDMAP project will be published jointly by the BEDMAP Consortium giving due acknowledgement to all participants, with copyright residing with SCAR.