polartoolkit.fetch.gravity

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polartoolkit.fetch.gravity#

gravity(version, region=None, spacing=None, registration=None, hemisphere=None, epsg=None, **kwargs)[source]#

Loads gravity anomaly data for the Arctic and Antarctic.

version=’antgg’ Antarctic-wide gravity data compilation of ground-based, airborne, and shipborne data, from Scheinert et al.[1]. Accessed from https://doi.pangaea.de/10.1594/PANGAEA.848168 Anomalies are at the ice surface, or bedrock surface in areas of no ice. These surfaces are defined by Bedmap2 and are relative to the ellipsoid.

version=’antgg-2021’ Updates on 2016 AntGG compilation. Accessed from https://doi.pangaea.de/10.1594/PANGAEA.971238?format=html#download Anomalies are at the ice surface, or bedrock surface in areas of no ice. These surfaces are defined by Bedmap2 and are relative to the ellipsoid.

version=’eigen’ Earth gravity grid (eigen-6c4) at 10 arc-min resolution at 10km geometric (ellipsoidal) height from Förste et al.[2]. originally from https://dataservices.gfz-potsdam.de/icgem/showshort.php?id=escidoc:1119897 Accessed via the Fatiando data repository fatiando-data/earth-gravity-10arcmin

Parameters:

  • version (str) – choose which version of gravity data to fetch.

  • region (tuple[float, float, float, float], optional) – region to clip the loaded grid to, in format [xmin, xmax, ymin, ymax], by default doesn’t clip

  • spacing (str or int, optional) – grid spacing to resample the loaded grid to, by default 10e3

  • registration (str, optional) – change registration with either ‘p’ for pixel or ‘g’ for gridline registration, by default is None.

  • hemisphere (str, optional) – choose which hemisphere to retrieve data for, “north” or “south”, by default None

  • epsg (str | None) – choose which region to retrieve data for, either “3031” or “3413”, by default None

  • kwargs (Any) – additional kwargs to pass to resample_grid and set the anomaly_type.

Keyword Arguments:

anomaly_type (str) – either ‘FA’ or ‘BA’, for free-air and bouguer anomalies, respectively. For antgg-update can also be ‘DG’ for gravity disturbance, or ‘Err’ for error estimates.

Returns:

Returns a loaded, and optional clip/resampled grid of either observed, free-air or Bouguer gravity anomalies.

Return type:

xarray.DataArray

References

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