Totten Glacier is the East Antarctic outlet that got cast as dependable. That reputation was always more shorthand than measurement: the glacier drains part of the Aurora Subglacial Basin, a vast interior catchment whose bed lies largely below sea level. Totten’s ice shelf is less a loose flap at the coast than a brace across a much larger system. If the brace thins, the room behind it can begin to empty.
The scale is difficult to picture, so here is the useful ledger:
| Item | What we know | Key source |
|---|---|---|
| Location | Budd Coast, Wilkes Land, East Antarctica | Totten Glacier |
| Drainage basin | Roughly 538,000 km² | Totten Glacier |
| Sea-level equivalent | At least 3.5 metres of global sea-level rise if the vulnerable ice were ultimately lost | Greenbaum et al., *Nature Geoscience* |
| Recent monitoring | GRACE/GRACE-FO gravimetry plus ICESat-2 laser altimetry | NASA Ice Sheets Indicator; ICESat-2 |
| Current signal | Multi-year height loss in the Totten catchment, consistent with buttressing loss and grounding-line retreat | Smith et al., *Journal of Glaciology* |
The satellites are not telling a simple story of “East Antarctica has started losing ice at West Antarctic rates.” That would be a clean headline and a poor description. A 2026 Nature analysis found that increased snowfall over parts of East Antarctica, including the region containing Totten, brought net Antarctic mass balance close to zero between 2021 and 2024. The authors describe that gain as probably temporary, driven by atmospheric circulation linked to a warming tropical ocean—not evidence that the ice sheet has become invulnerable.
That distinction matters because snowfall can mask a dynamic problem. Gravimetry weighs the whole ice sheet’s changing mass; altimetry measures the surface rising or sinking. One can see a short-lived atmospheric deposit on top while the outlet beneath continues to thin and accelerate. ICESat-2 observations through 2024 resolve height changes in coastal East Antarctica, including the Totten catchment, in a way older, sparser surveys could not. The picture is not a glacier vanishing on schedule. It is a glacier whose restraint is being eroded by several linked processes: warm modified Circumpolar Deep Water entering the ice-shelf cavity, basal melting, loss of shelf buttressing, and grounding-line retreat.
The Aurora Basin is the worrying geometry. Much of its floor is below sea level, so retreat can expose thicker ice to the ocean and make the next retreat easier. Totten is therefore a load-bearing wall in the least architectural sense of the phrase: not holding up a roof, but slowing the delivery of inland ice toward the sea. The wall does not need to fall today for its thinning to change the building’s future.
There is also a quieter lesson in the instruments. GRACE began weighing Earth’s mass distribution in 2002; GRACE-FO took over after the 2017–18 handover, while ICESat-2 launched in 2018. The “stable pole” was not suddenly born in the 2020s. It was finally being watched with enough continuity and precision to reveal that stability had conditions. East Antarctica’s weather can still briefly win the accounting. Its outlet glaciers are keeping a different book.
Sources
- NASA, “Ice Sheets” Earth Indicator
- NASA/JPL GRACE Tellus
- NASA ICESat-2 mission
- Smith et al., “ICESat-2 land ice products resolve Greenland and Antarctic ice-sheet height changes,” *Journal of Glaciology*
- Pelle et al., “Subglacial discharge accelerates dynamic retreat of Aurora Subglacial Basin outlet glaciers,” *JGR: Earth Surface*
- Wang et al., “Multiyear tropical warm pool warming drives slowdown in Antarctic mass loss,” *Nature*
- Wikipedia, “Totten Glacier”
- Wikipedia, “Aurora Subglacial Basin”