A team of international scientists led by the British Antarctic Survey (BAS) has assembled the most detailed landscape map beneath Antarctica’s ice sheet. The map, called Bedmap3, uses more than 60 years of data obtained by satellites, planes, ships, and even dog-drawn sleds.
The updated map of Antarctica clearly shows the landscape beneath its massive ice sheet, including its tallest mountains and deepest canyons. Notably, data revisions show the thickest ice is found in an unnamed canyon in Wilkes Land, not in the Astrolabe Basin, as previously thought.
This ice measures 4,757 meters—over 15 times the height of the Shard in the UK. The new map, Bedmap3, is crucial for studying how the ice sheet interacts with the bedrock and helping scientists predict Antarctica’s response to climate change.
Bedmap3 is the third and most refined map of Antarctica’s rock bed since efforts began in 2001. It features over 82 million data points—more than double the previous versions—displayed at a resolution of 500 meters.
Recent surveys have filled knowledge gaps in East Antarctica, the South Pole, the Antarctic Peninsula, and the Transantarctic Mountains. The new map provides a clearer outline of deep valleys and rocky mountains peeking through the ice and improved details on the ice sheet’s height, shape, and floating ice shelves along the coastline. This data advances our understanding of Antarctica’s geology and ice dynamics.
The updated map of Antarctica also offers a detailed view of grounding lines, where ice transitions from land to ocean and begins floating. Scientists use radar, seismic reflection, and gravity measurements to map the rock bed beneath the ice. By subtracting this landscape from the ice’s shape and elevation, they’ve uncovered intriguing data:
- Total volume of Antarctic ice, including ice shelves: 27.17 million cu km
- Total area of Antarctic ice, including ice shelves: 13.63 million sq km
- Mean thickness of Antarctic ice, including ice shelves: 1,948 m. (Excluding ice shelves: 2,148 m)
- Potential global sea-level rise if all ice melted: 58 m
These figures are critical for understanding the vastness of Antarctica’s ice and its potential impact on global sea levels.
Dr Hamish Pritchard, a glaciologist at BAS and lead author on the study detailing the new map, says:
“This is the fundamental information that underpins the computer models we use to investigate how the ice will flow across the continent as temperatures rise. Imagine pouring syrup over a rock cake – all the lumps and bumps will determine where the syrup goes and how fast. And so it is with Antarctica: some ridges will hold up the flowing ice; the hollows and smooth bits are where that ice could accelerate.”
Peter Fretwell, mapping specialist and co-author at BAS, says:
“In general, it’s become clear the Antarctic Ice Sheet is thicker than we originally realized and has a larger volume of ice grounded on a rock bed below sea level. This puts the ice at greater risk of melting due to the incursion of warm ocean water occurring at the continent’s fringes. What Bedmap3 is showing us is that we have got a slightly more vulnerable Antarctica than we previously thought.”
Journal Reference:
- Pritchard, H.D., Fretwell, P.T., Fremand, A.C. et al. Bedmap3 updated the ice bed and the surface and thickness gridded datasets for Antarctica. Sci Data 12, 414 (2025). DOI: 10.1038/s41597-025-04672-y
Source: Tech Explorist
