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South Pole Polygon

vectorGeoJSONPolygonEPSG:4326tinybundled

A polygon encircling the south pole in EPSG:4326. Exercises polar projection singularities where area and centroid calculations silently diverge.

Polygon geometry of south_pole_polygon, rendered from the case's data
Polygon geometry, rendered from the case's actual geometry. Scale is normalized to the viewport and is not comparable between cases.
Property Value
Case ID south_pole_polygon
Category vector
Format GeoJSON
Geometry type Polygon
CRS EPSG:4326
Location South Pole — 90.00°W, 89.50°S → 90.00°E, 84.00°S
Test tier unit
Size class tiny
Storage class bundled
Redistributable yes
Loader geopandas
Status validated

Use this case

import pytest


@pytest.mark.geocase_case("south_pole_polygon")
def test_south_pole_polygon(geocase_case) -> None:
    data = geocase_case.load()
    assert data is not None

Use GeoCase in your tests

Install the complete set of vector, raster, and NetCDF dependencies:

pip install "geocase[all]"

View GeoCase on PyPI.

What this case checks

Ensure polygon-based utilities handle geometries near the south pole without crashing or producing wildly incorrect area calculations.

Risk types covered

Expected behavior

Assertion Expected
expect_loadable yes
expect_valid_geometry yes
expect_crs yes
expected_epsg 4326
expected_geometry_types Polygon

Notes

A GeoJSON Polygon that encircles the south pole at latitude 85°S.

Purpose

Mirrors north_pole_polygon for the southern hemisphere. Antarctic projections (EPSG:3031 — Antarctic Polar Stereographic) and sea-ice workflows need polygons that enclose the south pole.

Geometry

A closed ring at 85°S with vertices at longitudes −45°, −135°, 135°, and 45°. The winding order is reversed relative to the north-pole case so the interior still contains the pole (counter-clockwise on the sphere, clockwise in projected 2-D for a south-polar view).

Edge-case value

Concern Detail
Area distortion Same as north pole — equirectangular area is meaningless
Reprojection Must work with EPSG:3031 and similar Antarctic CRS
Winding order Opposite to the north-pole case if viewed in 2-D
Rendering Web Mercator clips below ~−85.06°

Required capabilities

  • load
  • geometry-validation
  • reprojection

Files

Browse this case on GitHub

Source and license

  • Source: geocase-curated
  • License: MIT

Tags

crs edge_case geojson polar pole polygon south_pole vector