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Glaciers — introduction#

earthlens ships a single glaciers backend that fetches glacier outlines and fluctuations from three open sources and returns them either as a pyramids FeatureCollection (outlines) or a tidy pandas.DataFrame (fluctuations). The output shape is per instance — it follows the dataset you pick — and aggregate= is rejected for both shapes (these are pre-computed inventories / measurements, not gridded fields).

Three sources are covered:

  • RGI 7.0 (Randolph Glacier Inventory) — global glacier outlines, one shapefile per GTN-G first-order region (regions 01–19). Served openly — no login — by the UNESCO IHP-WINS mirror (the NSIDC host is Earthdata-gated, and the backend never touches it). Vector.
  • GLIMS (Global Land Ice Measurements from Space) — time-series glacier outlines (a glacier can have several outlines with different acquisition dates), queried by bounding box through the open GLIMS GeoServer WFS. Vector.
  • WGMS — the Fluctuations of Glaciers (FoG) database: mass balance, front variation (length change), and glacier state, as tabular CSV tables. Open download. Tabular.

This page orients the backend. For the hands-on walkthrough see Usage and the shipped dataset ids on the Available datasets page; the rendered API is the Reference page.

Two design points#

Per-instance OUTPUT_KIND. RGI and GLIMS outlines are vector; WGMS fluctuations are tabular. The resolved dataset's output_kind is copied onto the backend's OUTPUT_KIND at construction, so download() returns a FeatureCollection for rgi:outlines / glims:outlines and a DataFrame for the wgms:* datasets. The EarthLens facade reads it to know the return shape and to reject aggregate=.

Region-download-then-clip (RGI). RGI ships per GTN-G region (each region is a multi-MB shapefile zip), so the backend maps your request bounding box to the overlapping region(s), downloads and caches each region zip once, reads the shapefile inside it via pyramids FeatureCollection.read_file, reprojects to EPSG:4326 if needed, and clips to the bbox. A region= override (a GTN-G region id such as "11") skips the bbox→region step.

Authentication#

None. All three sources are open — IHP-WINS (RGI), the GLIMS WFS, and the WGMS FoG download — so the backend ships no auth module and needs no credentials.

Licenses / citations#

On a successful download the resolved dataset's citation is logged once:

  • RGI 7.0 — RGI 7.0 Consortium (2023), DOI 10.5067/F6JMOVY5NAVZ, CC-BY-4.0.
  • GLIMS — GLIMS and NSIDC (nsidc-0272), CC-BY-4.0; cite the contributing analysts.
  • WGMS — WGMS (2026), Fluctuations of Glaciers Database, DOI 10.5904/wgms-fog-2026-02-10.