Bedmap3: New Map of Antarctica’s Hidden Bed and Ice
Why in the news
Scientists released Bedmap3, a fuller picture of the terrain beneath Antarctica’s ice, which sharpens estimates of future sea-level rise.
Key facts
- Builds on Bedmap2 with 84 new surveys from 15 data sources.
- Adds 52 million data points and 1.9 million line-km of measurements.
- Better understanding of mountain ranges, East Antarctica’s deep interior, West Antarctic coasts and the Antarctic Peninsula.
Main discoveries
| Finding | Detail |
|---|---|
| Thickest ice | 4.7 km at Wilkes Land (76.052° S, 118.378° E), more than half Everest’s height |
| Earlier belief | Astrolabe Basin was thought to hold the thickest ice |
| Average thickness | 1.9 km including ice shelves |
| Grounded ice | More lies below sea level than known |
Significance
- Ice grounded below sea level is more exposed to warm ocean water, so Antarctica is more vulnerable (Peter Fretwell, British Antarctic Survey).
- The Scientific Data study (10 March) says the ice sheet’s response to warming is the largest uncertainty in future sea-level rise.
- Better models of past and future ice change and ice-bedrock interaction.
Exam angle
- Bedmap3: Antarctica’s subglacial mapping; thickest ice at Wilkes Land.