Outlet glacier speeds
Speed averaged over a fixed set of trunk pixels that carry valid data in every year reported — years below 90% coverage are dropped, not interpolated, because feature tracking succeeds preferentially on fast ice and a sparse year is biased fast. Each figure is measured on grounded ice wherever grounded trunk exists, because ice crossing the grounding line is what raises sea level; a floating shelf displaces no extra water however fast it moves. Of these 13 glaciers only 4 show a change that exceeds twice its own uncertainty. The other 9 are reported as no detectable change, which is the honest result rather than a gap.
| Glacier | Domain | Trunk km² | Speed m/yr | Fitted change | Verdict |
|---|---|---|---|---|---|
| Getz Ice Shelf | grounded | 234 | 510 | +22.4% | significant |
| Pine Island Glacier | grounded | 1,356 | 2,001 | +16.3% | significant |
| Thwaites Glacier | grounded | 4,763 | 1,023 | +8.5% | significant |
| Jutulstraumen | grounded | 12 | 199 | -5.3% | significant |
| Smith and Kohler Glaciers | grounded | 9 | 342 | +42.2% | no detectable change |
| Mertz Glacier | grounded | 9 | 896 | -2.9% | no detectable change |
| Lambert Glacier | grounded | 59 | 131 | +8.8% | no detectable change |
| Denman Glacier | grounded | 690 | 952 | -0.7% | no detectable change |
| Rutford Ice Stream | grounded | 752 | 378 | -6.6% | no detectable change |
| Shirase Glacier | grounded | 518 | 923 | -0.7% | no detectable change |
| Totten Glacier | grounded | 417 | 456 | -1.5% | no detectable change |
| Institute Ice Stream | grounded | 1,267 | 352 | -0.2% | no detectable change |
| Recovery Glacier | grounded | 4,077 | 172 | -0.2% | no detectable change |
Grounded ice against its floating shelf
Every glacier above with a measurable shelf is also measured on that shelf, over the years the two share. On 2 of them the grounded ice and the shelf in front of it are moving in opposite directions — the distinction most coverage of Antarctic ice loses, and the one that decides whether a number means anything for sea level. See all 11 compared →
There is no continent-wide number here
Coverage before 1999 is negligible and no continent-wide acceleration figure is defensible from this product. Per-glacier series are only reported where the coverage gate is met. Each box is a fixed window around the trunk, not a drainage basin, so these are speeds over a measured area and not mass-balance figures.