Previous continent scale bed elevation mapping

Since 1983, one map of bed elevation in Antarctica has been widely adopted. This is Sheet 3 in the SPRI Glaciological and Geophysical Folio Series by Drewry and Jordan (1983). The contours were drawn from ice thickness data collected on sparse surface traverses and by airborne surveys, including a major airborne campaign involving Scott Polar Research Institute, National Science Foundation and Technical University of Denmark, which covered about one third of the continent at 100 km line-spacing. Contours of bed elevation were drawn over the entire continent although in many areas there were more than 500 km between measurements. Figure 1 shows the coverage of data that were used in this compilation in terms of the number of measurements available in each 100 km grid cell.

Despite its limitations and well-known shortcomings, the SPRI Folio Sheet 3 is still a commonly cited publication in papers from a wide variety of scientific disciplines. This is a clear indication that there is a major requirement for bed elevation data within the scientific community. While the SPRI compilation could be considered as the state-of-the-art in 1983, it is no longer adequate and is no longer the best we can achieve. Considerable advances in data and technology will now allow us to make big improvements in the coverage and accuracy of the product.

  • new ice-thickness data have now been collected by many nations, covering many of the sectors not visited before 1983.
  • Satellite altimetry has almost entirely removed the need to rely on inaccurate barometric altimetry Mapping has been refined so that areas that are classified as ice-free can now be easily incorporated into a bed elevation compilation
  • Coastal bathymetry has been much improved and can be easily merged with continental bed elevation
  • Advanced GIS systems now allow incorporation of many types of subsidiary data into a single determination of bed elevation