Scientific field notes
See the field notes for all glaciers
How the 3D view of this glacier is made: what was measured, what was modelled, and how each is checked. Every number on this page is for the tongue (section 1) only, and is as recorded in the project's source ledger or marked as computed.
One page of field notes for each glacier whose 3D view has a surface for every year: what was measured, what was modelled and how each is checked. Choose a glacier.
1Study area: the tongue
2Ice surface through time: how each year was made
One column per year. Top: how the surface was found and its 1σ uncertainty. Below: the measured surfaces it hangs on, what shapes the change between them, what checks it, and what is fixed. Click a year for the full text, the ICESat-2, ASTER and stake numbers.
Official glacier elevation models. We are in contact with GLAMOS and swisstopo about implementing the glacier elevation models described on swisstopo geodata for glacial purposes. The yearly surfaces on this page are our own model, built from the swisstopo surveys as described below; they are not those official models.
Click a year in the chart to show its details here.
Kinds of surface
measured: a dated DEM or lidar surface. interpolated: between two measured surfaces. extrapolated: beyond the last one, at its rate. provisional: 2026. Date: every year is the surface on 30 September of that year (the end of the glaciological year). A measured surface is moved from its survey day to 30 September by the same model, so the surface shown for a surveyed year is not the raw survey: it is the survey surface lowered by the melt between the survey day and 30 September (for a survey in August, the weeks in between).
Sharing the loss between years
Uncertainty
Median over the tongue ice, red whisker the 90th percentile. Calibrated on the same ICESat-2 shots. 2026 has none yet: it is provisional and its balance was read from the GLAMOS figure.
Independent checks
ICESat-2 also fitted the 2023 anchor day and σ, so it is not independent (rmse is leave-one-granule-out). ASTER and stakes are checks only. Click a year for their numbers.