On 1 October the Swiss glacier monitoring network, GLAMOS, and the Swiss Academy of Sciences published this year's numbers. Swiss glaciers lost 5.5% of their total ice volume in 2026, and almost 20% over the last five years. The Aletsch, the longest glacier in the Alps, had its biggest melt on record.
One figure in the report is easy to picture on a printed map: this summer the freezing level sat above 4,000 m for 76 days between May and September. That is more than double the average and a national record.
I built the Aletsch to see what 4,000 m means on a model you can hold.
The model
It is a 14 km square around the heart of the glacier, where its great ice streams meet, printed at 150 mm with no exaggeration. That makes the scale 1:93,333. The ground in the frame runs from 2,011 m to 4,076 m, and with a 4 mm base the whole thing stands 26.2 mm tall.
For those 76 days the freezing level was somewhere above 25.3 mm on a 26.2 mm model. At most the top 0.9 mm of this print could have stayed below freezing.
You can't print one summer
The thinning itself is harder to show. At the lowest monitoring point on the Aletsch tongue the ice got 13 m thinner this year. At this scale that is 0.14 mm, less than one 0.16 mm layer. A single year of record melt disappears into the layer lines.
The other caveat is the data. Elevation data comes from surveys flown at a particular time, so the ice surface in any model is a snapshot, and with the glacier losing metres a year the real surface is already lower than the one you print.
What a print can show is where the snow survives.
Print the snow line instead
A glacier stays healthy when snow lasts through the summer high enough to feed it. You can put that height on a print with one filament change: print the terrain in grey, then switch to white at a chosen height, and everything above it comes out white. It costs one swap and about 16 g of purge, as the purge post worked out.
Here are the heights worth printing on this model, and the layer to swap at:
| Height | What it marks | Swap at |
|---|---|---|
| 3,100 m | Aletsch snow line, 2025 | 15.7 mm |
| 3,200 m | Aletsch record snow line, 2022 | 16.7 mm |
| 3,500 m | No snow left even here by September 2026 | 20.0 mm |
| 4,000 m | Freezing level for 76 days, summer 2026 | 25.3 mm |
Print two copies, one swapped at 3,200 m and one at 4,000 m, and put them side by side. The first is a bad year. The second is this year's summer heat, and it leaves only the tips of the summits white. Nobody needs a chart to read the difference.
Making one
- Open this exact framing in the map maker, or frame your own glacier anywhere.
- Keep the exaggeration at 1x. The relief is already 22 mm, and the heights in the table only hold at 1x.
- In the slicer, find the layer nearest your swap height and add a filament change there. PrusaSlicer, Bambu Studio and OrcaSlicer all do this from the layer slider.
- Change the print width or the frame, and the numbers change. The formula above works for any model: base, plus height above the lowest point, times print width over real width.
The national parks piece has more on framing valleys, and this one covers when to leave the exaggeration alone.
Sources
The GLAMOS and SCNAT findings as reported by Swissinfo and Phys.org. The 2022 and 2025 Aletsch snow lines come from the glacierchange.blog satellite record.