ATLAS

Official versionOMEGA-24-1-4Sheet 4 of 5 of the dossier Lands beyond the ice wall

Official view: mapping Antarctica above and below the ice

Open datasets from Bedmap3, REMA and radar surveys, which show the shape of the continent and its bed.

A colour map of Antarctica showing the rock bed under the ice, with blue areas below sea level.
Subglacial topography and bathymetry of Antarctica built from BEDMAP data, with the ice removed (Paul V. Heinrich, 2008). Paul V. heinrich · CC BY · Wikimedia Commons

Summary

A wall of ice with worlds behind it is a claim about maps, so this sheet looks at how Antarctica is mapped today. The mapping is the work of public institutions that publish their data. Bedmap3, led by the British Antarctic Survey and released in March 2025, merges more than six decades of measurements by plane, satellite, ship and even dog sled into 82 million data points on a 500 m grid. It reveals the rock bed beneath the ice, with the tallest mountains and deepest canyons, and gives a mean ice thickness of 1,948 m including ice shelves. Its authors note that the ice sheet is thicker than first thought.

The Reference Elevation Model of Antarctica, produced by the Polar Geospatial Center from satellite stereo imagery of about 0.5 m resolution, offers surface elevation at 2 m under an open CC BY 4.0 licence. Radar surveys also revealed a subglacial lake, Lake Vostok, announced in Nature in 1996. These products show a continent of ice, rock and water whose shape is measured from space, from the air and on the ground. Nothing in these datasets points to another continent, and anyone can download the data to check.

Official version

  1. Official version

    Bedmap3, a map of the landscape beneath Antarctica's ice led by the British Antarctic Survey, incorporates more than six decades of survey data acquired by planes, satellites, ships and even dog-drawn sleds.

  2. Official version

    Bedmap3 includes more than double the number of previous data points, 82 million, rendered on a 500 m grid; recent surveys filled big gaps around the South Pole, the Antarctic Peninsula and the Transantarctic Mountains.

  3. Official version

    According to the Bedmap3 figures, the mean thickness of Antarctic ice including ice shelves is 1,948 m, and melting all of it would raise global sea level by 58 m.

  4. Official version

    BAS mapping specialist Peter Fretwell said it has become clear that the Antarctic Ice Sheet is thicker than originally realised and holds more ice grounded on a rock bed below sea level.

  5. Official version

    The Reference Elevation Model of Antarctica (REMA), from the Polar Geospatial Center, provides 2 m resolution elevation models built from high-resolution (about 0.5 m) imagery of the Maxar satellites, released under a CC BY 4.0 licence.

    • Reference Elevation Model of Antarctica (REMA), Registry of Open Data on AWS (Polar Geospatial Center)
      REMA data is constructed from in-track and cross-track high-resolution (~0.5 meter) imagery acquired by the Maxar constellation of optical imaging satellites.
  6. Official version

    Airborne ice-penetrating radar surveys in the early 1970s detected readings suggesting a liquid freshwater lake under the ice; the discovery of Lake Vostok was published in Nature on 20 June 1996.

    • Lake Vostok, Wikipedia
      they detected unusual radar readings at the site which suggested the presence of a liquid freshwater lake below the ice
Play on YouTube (third-party content)
"BEDMAP of Antarctica", video of the British Antarctic Survey presenting its map of the landscape beneath the ice.
British Antarctic Survey