metadata.json

{
  "title": "World Gravity Map 2012 (WGM2012) \u2014 Modernized GeoParquet (Bouguer + Free-air)",
  "source": "Bureau Gravim\u00e9trique International (BGI), accessed via NORA Research Lab's AGDFS API",
  "citation": "Bonvalot, S., Briais, A., Kuhn, M., Peyrefitte, A., Vales, N., Biancale, R., Gabalda, G., Moreaux, G., Reinquin, F. & Sarrailh, M. (2012). Global grids: World Gravity Map (WGM2012). Bureau Gravimetrique International. https://doi.org/10.18168/bgi.23",
  "native_resolution": "2 arc-minutes x 2 arc-minutes",
  "crs": "EPSG:4326",
  "gravity_products": [
    "Bouguer anomaly (mGal)",
    "Free-air anomaly, Molodenski (mGal)"
  ],
  "known_gaps": "Isostatic anomaly (Airy-Heiskanen, Tc=30km) is part of WGM2012 but not currently exposed by the AGDFS gravity endpoint, so it is not included in this release. Can be added later if that layer becomes available.",
  "derived_from_models": [
    "EGM2008",
    "DTU10",
    "ETOPO1 (terrain correction)"
  ],
  "total_points": 58320000,
  "value_ranges_mgal": {
    "bouguer_anomaly_mgal": [
      -528.96435546875,
      1005.0118408203125
    ],
    "freeair_anomaly_mgal": [
      -388.63299560546875,
      990.968017578125
    ]
  },
  "format": "GeoParquet (EPSG:4326 point geometry), partitioned by latitude band",
  "license": "Academic/research use per BGI terms \u2014 no warranty on accuracy; BGI is not responsible for consequences of use.",
  "modernized_by": "NORA Research Lab",
  "modernization_date": "2026-09-01",
  "pipeline": "AGDFS tiled fetch -> Standardization -> Modern Format -> Validation -> Metadata -> AI/API Ready"
}