name: geospatial-projection-selection
description: Guidance on selecting appropriate CRS projections for geospatial distance calculations, especially EPSG:4087 for global analyses.
EPSG:4087 — World Equidistant Cylindrical
- Use case: Global distance calculations where a single consistent projection is needed
- Properties: Equidistant along meridians; distances measured in meters
- CRS string:
EPSG:4087
gdf_projected = gdf.to_crs('EPSG:4087')
When to use EPSG:4087 vs other projections
| Projection |
Use case |
| EPSG:4326 |
Spatial containment, lat/lon storage (unprojected) |
| EPSG:4087 |
Global distance calculations in meters |
| Custom aeqd |
Local distance calculations centered on a specific point |
| EPSG:3857 |
Web mapping (NOT for distance/area calculations) |
Important notes for Pacific plate analysis
- The Pacific plate crosses the antimeridian (±180° longitude)
- Do NOT project the Pacific plate polygon for containment checks — use EPSG:4326
- Do project points and boundaries to EPSG:4087 for distance calculations
- Use
make_valid() from shapely.validation on plate polygons that may have topology issues
By