antarctic_plots.fetch

class EarthDataDownloader

Bases: object

Adapted from IcePack: icepack/icepack Either pulls login details from pre-set environment variables, or prompts user to input username and password.

basal_melt(variable='w_b')

Antarctic ice shelf basal melt rates for 1994-2018 from satellite radar altimetry. from Adusumilli et al. “Interannual Variations in Meltwater Input to the Southern Ocean from Antarctic Ice Shelves.” Nature Geoscience 13, no. 9 (September 2020): 616-20. https://doi.org/10.1038/s41561-020-0616-z.

accessed from http://library.ucsd.edu/dc/object/bb0448974g

reading files and preprocessing from supplied jupyternotebooks: sioglaciology/ice_shelf_change

Units are in m/yr

Parameters:

variable (str) – choose which variable to load, either ‘w_b’ for basal melt rate, ‘w_b_interp’, for basal melt rate with interpolated values, and ‘w_b_uncert’ for uncertainty

Returns:

Returns a dataarray of basal melt rate values

Return type:

xr.DataArray

basement(region=None, spacing=None, registration=None)

Load a grid of basement topography. Offshore and sub-Ross Ice Shelf basement topography. from Tankersley et al. 2022: https://onlinelibrary.wiley.com/doi/10.1029/2021GL097371 accessed from https://doi.pangaea.de/10.1594/PANGAEA.941238 offshore data from Lindeque et al. 2016: https://doi.org/10.1002/2016GC006401

Elevations are referenced to WGS84 (? need to check this!)

Returns:

dataarray of basement depths

Return type:

xr.DataArray

Parameters:

• region (tuple[float, float, float, float] | None) –

• spacing (float | None) –

• registration (str | None) –

bedmachine(layer, reference='eigen-6c4', region=None, spacing=None, registration=None, **kwargs)

Load BedMachine v3 data, from Morlighem et al. 2020: https://doi.org/10.1038/s41561-019-0510-8

Cited as: Morlighem, M. 2022. MEaSUREs BedMachine Antarctica, Version 3. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/FPSU0V1MWUB6

Accessed from NSIDC via https://nsidc.org/data/nsidc-0756/versions/3. Also available from ldeo-glaciology/pangeo-bedmachine

Referenced to the EIGEN-6C4 geoid. To convert to be ellipsoid-referenced, we add the geoid grid. use reference=’ellipsoid’ to include this conversion in the fetch call.

Surface and ice thickness are in ice equivalents. Actual snow surface is from REMA (Howat et al. 2019), and has had firn thickness added(?) to it to get Bedmachine Surface.

To get snow surface: surface+firn To get firn and ice thickness: thickness+firn

Here, icebase will return a grid of surface-thickness This should be the same as snow-surface - (firn and ice thickness)

Parameters:

• layer (str) – choose which layer to fetch: ‘bed’, ‘dataid’, ‘errbed’, ‘firn’, ‘geoid’, ‘mapping’, ‘mask’, ‘source’, ‘surface’, ‘thickness’; ‘icebase’ will give results of surface-thickness

• reference (str) – choose whether heights are referenced to ‘eigen-6c4’ geoid or the ‘ellipsoid’ (WGS84), by default is eigen-6c4’

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

• spacing (str or int, optional) – grid spacing to resample the loaded grid to, by default 500m

• registration (str | None) –

• kwargs (typing.Any) –

Returns:

Returns a loaded, and optional clip/resampled grid of Bedmachine.

Return type:

xr.DataArray

bedmap2(layer, reference='eigen-gl04c', region=None, spacing=None, registration=None, fill_nans=False, **kwargs)

Load bedmap2 data as xarray.DataArrays from Fretwell et a. 2022: BEDMAP2 - Ice thickness, bed and surface elevation for Antarctica - gridding products (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. DOI: https://doi.org/10.5285/FA5D606C-DC95-47EE-9016-7A82E446F2F2 accessed from https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=fa5d606c-dc95-47ee-9016-7a82e446f2f2.

All grids are by default referenced to the EIGEN-GL04C geoid. Use the reference=’ellipsoid’ to convert to the WGS-84 ellipsoid or reference=’eigen-6c4’ to convert to the EIGEN-6c4 geoid.

Unlike Bedmachine data, Bedmap2 surface and icethickness contain NaN’s over the ocean, instead of 0’s. To fill these NaN’s with 0’s, set fill_nans=True. Note, this only makes since if the reference is the geoid, therefore, if reference=’ellipsoid and fill_nans=True, the nan’s will be filled before converting the results to the geoid (just for surface, since thickness isn’t relative to anything).

Parameters:

• layer (str) – choose which layer to fetch: “bed”, “coverage”, “grounded_bed_uncertainty”, “icemask_grounded_and_shelves”, “lakemask_vostok”, “rockmask”, “surface”, “thickness”, “thickness_uncertainty_5km”, “gl04c_geiod_to_WGS84”, “icebase”

• reference (str) – choose whether heights are referenced to the ‘eigen-6c4’ geoid, the WGS84 ellipsoid, ‘ellipsoid’, or by default the ‘eigen-gl04c’ geoid.

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

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

• registration (str, optional,) – choose between ‘g’ (gridline) or ‘p’ (pixel) registration types, by default is the original type of the grid

• fill_nans (bool, optional,) – choose whether to fill nans in ‘surface’ and ‘thickness’ with 0. If converting to reference to the geoid, will fill nan’s before conversion, by default is False

• kwargs (typing.Any) –

Returns:

Returns a loaded, and optional clip/resampled grid of Bedmap2.

Return type:

xr.DataArray

bedmap_points(version, region=None)

Load bedmap point data, choose from Bedmap 1, 2 or 3

version == ‘bedmap1’

from Lythe, M. B. and Vaughan, D. G. 2000. BEDMAP-bed topography of the Antarctic, British Antarctic Survey, Natural Environment Research Council DOI: https://doi.org/10.5285/f64815ec-4077-4432-9f55-0ce230f46029 accessed from https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01619

version == ‘bedmap2’

from Fretwell et al. 2013. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica, The Cryosphere, 7, 375-393 DOI: https://doi.org/10.5285/2fd95199-365e-4da1-ae26-3b6d48b3e6ac accessed from https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01616

version == ‘bedmap3’

Publication not released yet DOI: https://doi.org/10.5285/91523ff9-d621-46b3-87f7-ffb6efcd1847 accessed from https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01614

Parameters:

• version (str) – choose between ‘bedmap1’, ‘bedmap2’, or ‘bedmap3’ point data

• region (tuple[float, float, float, float], optional) – add a GMT region to subset the data by, by default None

Returns:

Return a dataframe, optionally subset by a region

Return type:

pd.DataFrame

crustal_thickness(version, region=None, spacing=None, registration=None)

Load 1 of x ‘versions’ of Antarctic crustal thickness grids.

version=’shen-2018’ Crustal thickness (excluding ice layer) from Shen et al. 2018: The crust and upper mantle structure of central and West Antarctica from Bayesian inversion of Rayleigh wave and receiver functions. https://doi.org/10.1029/2017JB015346 Accessed from https://sites.google.com/view/weisen/research-products?authuser=0

version=’an-2015’ Crustal thickness (distance from solid (ice and rock) top to Moho discontinuity) from An et al. 2015: S-velocity Model and Inferred Moho Topography beneath the Antarctic Plate from Rayleigh Waves. J. Geophys. Res., 120(1),359-383, doi:10.1002/2014JB011332 Accessed from http://www.seismolab.org/model/antarctica/lithosphere/index.html#an1s File is the AN1-CRUST model, paper states “Moho depths and crustal thicknesses referred to below are the distance from the solid surface to the Moho. We note that this definition of Moho depth is different from that in the compilation of AN-MOHO”. Unclear, but seems moho depth is just negative of crustal thickness. Not sure if its to the ice surface or ice base.

Parameters:

• version (str) – Either ‘shen-2018’, will add later: ‘lamb-2020’, ‘an-2015’, ‘baranov’, ‘chaput’, ‘crust1’, ‘szwillus’, ‘llubes’, ‘pappa’, ‘stal’

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

• spacing (int, optional) – grid spacing to resample the loaded grid to, by default spacing is read from downloaded files

• registration (str | None) –

Returns:

Returns a loaded, and optional clip/resampled grid of crustal thickness.

Return type:

xr.DataArray

deepbedmap(region=None, spacing=None, registration=None)

Load DeepBedMap data, from Leong and Horgan, 2020: https://doi.org/10.5194/tc-14-3687-2020 Accessed from https://zenodo.org/record/4054246#.Ysy344RByp0

Parameters:

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

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

• registration (str | None) –

Returns:

Returns the filepath of DeepBedMap.

Return type:

str

etopo(region=None, spacing=None, registration=None)

Loads a grid of Antarctic topography from ETOPO1. Originally at 10 arc-min resolution, reference to mean sea-level

originally from https://www.ncei.noaa.gov/access/metadata/landing-page/bin/iso?id=gov.noaa.ngdc.mgg.dem:316 # noqa: E501 Accessed via the Fatiando data repository fatiando-data/earth-topography-10arcmin # noqa: E501

Parameters:

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

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

• registration (str | None) –

Returns:

Returns a loaded, and optional clip/resampled grid of topography.

Return type:

xr.DataArray

geoid(region=None, spacing=None, registration=None, **kwargs)

Loads a grid of Antarctic geoid heights derived from the EIGEN-6C4 spherical harmonic model of Earth’s gravity field. Originally at 10 arc-min resolution. Negative values indicate the geoid is below the ellipsoid surface and vice-versa. To convert a topographic grid which is referenced to the ellipsoid to be referenced to the geoid, add this grid. To convert a topographic grid which is referenced to the geoid to be reference to the ellipsoid, subtract this grid.

originally from https://dataservices.gfz-potsdam.de/icgem/showshort.php?id=escidoc:1119897 # noqa: E501 Accessed via the Fatiando data repository fatiando-data/earth-geoid-10arcmin # noqa: E501

Parameters:

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

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

• registration (str | None) –

• kwargs (typing.Any) –

Returns:

Returns a loaded, and optional clip/resampled grid of geoid height.

Return type:

xr.DataArray

geomap(version='faults', region=None)

Data from GeoMAP accessed from https://doi.pangaea.de/10.1594/PANGAEA.951482?format=html#download

from Cox et al. (2023): A continent-wide detailed geological map dataset of Antarctica. Scientific Data, 10(1), 250, https://doi.org/10.1038/s41597-023-02152-9

Parameters:

• version (str, optional) – choose which version to retrieve, “faults”, “units”, “sources”, or “quality”, by default “faults”

• region (tuple[float, float, float, float], optional) – return only data within this region, by default None

Returns:

Returns a geodataframe

Return type:

gpd.GeoDataFrame

get_fetches()

get all the fetch functions defined in this module.

Returns:

names of each fetch function

Return type:

list[str, tuple[float, float, float, float] ]

ghf(version, region=None, spacing=None, registration=None, **kwargs)

Load 1 of 6 ‘versions’ of Antarctic geothermal heat flux data.

version=’an-2015’ From At et al. 2015: emperature, lithosphere-asthenosphere boundary, and heat flux beneath the Antarctic Plate inferred from seismic velocities http://dx.doi.org/doi:10.1002/2015JB011917 Accessed from http://www.seismolab.org/model/antarctica/lithosphere/index.html

version=’martos-2017’ From Martos et al. 2017: Heat flux distribution of Antarctica unveiled. Geophysical Research Letters, 44(22), 11417-11426, https://doi.org/10.1002/2017GL075609 Accessed from https://doi.pangaea.de/10.1594/PANGAEA.882503

version=’shen-2020’: From Shen et al. 2020; A Geothermal Heat Flux Map of Antarctica Empirically Constrained by Seismic Structure. https://doi.org/ 10.1029/2020GL086955 Accessed from https://sites.google.com/view/weisen/research-products?authuser=0 Used https://paperform.co/templates/apps/direct-download-link-google-drive/ to generate a direct download link from google drive page. https://drive.google.com/uc?export=download&id=1Fz7dAHTzPnlytuyRNctk6tAugCAjiqzR

version=’burton-johnson-2020’ From Burton-Johnson et al. 2020: Review article: Geothermal heat flow in Antarctica: current and future directions, https://doi.org/10.5194/tc-14-3843-2020 Accessed from supplementary material Choose for either of grid, or the point measurements

version=’losing-ebbing-2021’ From Losing and Ebbing 2021: Predicting Geothermal Heat Flow in Antarctica With a Machine Learning Approach. Journal of Geophysical Research: Solid Earth, 126(6), https://doi.org/10.1029/2020JB021499 Accessed from https://doi.pangaea.de/10.1594/PANGAEA.930237

version=’aq1’ From Stal et al. 2021: Antarctic Geothermal Heat Flow Model: Aq1. DOI: https://doi.org/10.1029/2020GC009428 Accessed from https://doi.pangaea.de/10.1594/PANGAEA.924857

Parameters:

• version (str) – Either ‘burton-johnson-2020’, ‘losing-ebbing-2021’, ‘aq1’,

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

• spacing (int, optional) – grid spacing to resample the loaded grid to, by default spacing is read from downloaded files

• registration (str | None) –

• kwargs (typing.Any) –

Returns:

Returns a loaded, and optional clip/resampled grid of GHF data.

Return type:

xr.DataArray

gia(version, region=None, spacing=None, registration=None)

Load 1 of 1 ‘versions’ of Antarctic glacial isostatic adjustment grids.

version=’stal-2020’ From Stal et al. 2020: Review article: The Antarctic crust and upper mantle: a flexible 3D model and framework for interdisciplinary research, https://doi.org/10.5194/tc-14-3843-2020 Accessed from https://doi.org/10.5281/zenodo.4003423

Parameters:

• version (str) – For now the only option is ‘stal-2020’,

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

• spacing (int, optional) – grid spacing to resample the loaded grid to, by default spacing is read from downloaded files

• registration (str | None) –

Returns:

Returns a loaded, and optional clip/resampled grid of GIA data.

Return type:

xr.DataArray

gravity(version, region=None, spacing=None, registration=None, **kwargs)

Loads 1 of 3 ‘versions’ of Antarctic gravity grids.

version=’antgg’ Antarctic-wide gravity data compilation of ground-based, airborne, and shipborne data, from Scheinert et al. 2016: New Antarctic gravity anomaly grid for enhanced geodetic and geophysical studies in Antarctica. DOI: https://doi.org/10.1002/2015GL067439 Accessed from https://doi.pangaea.de/10.1594/PANGAEA.848168

version=’antgg-update’ Preliminary compilation of Antarctica gravity and gravity gradient data. Updates on 2016 AntGG compilation. Accessed from https://ftp.space.dtu.dk/pub/RF/4D-ANTARCTICA/

version=’eigen’ Earth gravity grid (eigen-6c4) at 10 arc-min resolution at 10km geometric (ellipsoidal) height. originally from https://dataservices.gfz-potsdam.de/icgem/showshort.php?id=escidoc:1119897 # noqa: E501 Accessed via the Fatiando data repository fatiando-data/earth-gravity-10arcmin # noqa: E501

Parameters:

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

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

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

• registration (str | None) –

• kwargs (typing.Any) –

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:

xr.DataArray

groundingline(version='depoorter-2013')

Load the file path of two versions of groundingline shapefiles

version = “depoorter-2013” from https://doi.pangaea.de/10.1594/PANGAEA.819147 Supplement to Depoorter et al. 2013: https://doi.org/10.1038/nature12567

version = “measures-v2” from Mouginot, J., B. Scheuchl, and E. Rignot. (2017). MEaSUREs Antarctic Boundaries for IPY 2007-2009 from Satellite Radar, Version 2 [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/AXE4121732AD. accessed at https://nsidc.org/data/nsidc-0709/versions/2

Parameters:

version (str, optional) – choose which version to retrieve, by default “depoorter-2013”

Returns:

file path

Return type:

str

ibcso(layer, region=None, spacing=None, registration=None)

Load IBCSO v2 data, from Dorschel et al. 2022: The International Bathymetric Chart of the Southern Ocean Version 2. Scientific Data, 9(1), 275, https://doi.org/10.1038/s41597-022-01366-7

Accessed from https://doi.pangaea.de/10.1594/PANGAEA.937574?format=html#download

Parameters:

• layer (str) – choose which layer to fetch: ‘surface’, ‘bed’

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

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

• registration (str | None) –

Returns:

Returns a loaded, and optional clip/resampled grid of IBCSO data.

Return type:

xr.DataArray

ibcso_coverage(region)

Load IBCSO v2 data, from Dorschel et al. 2022: The International Bathymetric Chart of the Southern Ocean Version 2. Scientific Data, 9(1), 275, https://doi.org/10.1038/s41597-022-01366-7

Accessed from https://doi.pangaea.de/10.1594/PANGAEA.937574?format=html#download

Parameters:

region (tuple[float, float, float, float]) – GMT-format region to subset the data from.

Returns:

Returns a geodataframe of a subset of IBCSO v2 point measurement locations

Return type:

gpd.GeoDataFrame

ice_vel(region=None, spacing=5000.0, registration=None, **kwargs)

MEaSUREs Phase-Based Antarctica Ice Velocity Map, version 1: from Mouginot, Rignot, and Scheuchl 2019. MEaSUREs Phase-Based Antarctica Ice Velocity Map, Version 1. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/PZ3NJ5RXRH10. accessed from https://nsidc.org/data/nsidc-0754/versions/1#anchor-1 Data part of https://doi.org/10.1029/2019GL083826

Units are in m/yr

Parameters:

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

• spacing (float,) – grid spacing to resample the loaded grid to, by default 5e3, original spacing is 450m

• registration (str, optional) – set either ‘p’ for pixel or ‘g’ for gridline registration, by default is ‘g’

• kwargs (typing.Any) –

Returns:

Returns a calculated grid of ice velocity in meters/year.

Return type:

xr.DataArray

imagery()

Load the file path of Antarctic imagery geotiff from LIMA: https://lima.usgs.gov/fullcontinent.php will replace with below once figured out login issue with pooch MODIS Mosaic of Antarctica: https://doi.org/10.5067/68TBT0CGJSOJ Assessed from https://daacdata.apps.nsidc.org/pub/DATASETS/nsidc0730_MEASURES_MOA2014_v01/geotiff/

Returns:

file path

Return type:

str

magnetics(version, region=None, spacing=None, registration=None, **kwargs)

Load 1 of 3 ‘versions’ of Antarctic magnetic anomaly grid. from Golynsky et al. (2018). New magnetic anomaly map of the Antarctic. Geophysical Research Letters, 45, 6437- 6449. https://doi.org/10.1029/2018GL078153

version=’admap1’ ADMAP-2001 magnetic anomaly compilation of Antarctica. Accessed from https://admap.kongju.ac.kr/databases.html

version=’admap2’ ADMAP2 magnetic anomaly compilation of Antarctica. Accessed from https://doi.pangaea.de/10.1594/PANGAEA.892723?format=html#download

version=’admap2_gdb’ Geosoft-specific .gdb abridged files. Accessed from https://doi.pangaea.de/10.1594/PANGAEA.892722?format=html#download

Parameters:

• version (str) – Either ‘admap1’, ‘admap2’, or ‘admap2_gdb’

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

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

• registration (str | None) –

• kwargs (typing.Any) –

Returns:

Returns a loaded, and optional clip/resampled grid of magnetic anomalies.

Return type:

xr.DataArray

mass_change(version='ais_dhdt_floating')

Ice-sheet height and thickness changes from ICESat to ICESat-2. from Smith et al. “Pervasive Ice Sheet Mass Loss Reflects Competing Ocean and Atmosphere Processes.” Science, April 30, 2020, eaaz5845. https://doi.org/10.1126/science.aaz5845.

Choose a version of the data to download with the format: “ais_VERSION_TYPE” where VERSION is “dhdt” for total thickness change or “dmdt” for corrected for firn-air content. TYPE is “floating” or “grounded”

add “_filt” to retrieve a filtered version of the data.

accessed from https://digital.lib.washington.edu/researchworks/handle/1773/45388

Units are in m/yr

Returns:

Returns a calculated grid of Antarctic ice mass change in meters/year.

Return type:

xr.DataArray

Parameters:

version (str) –

measures_boundaries(version)

Load various files from the MEaSUREs Antarctic Boundaries for IPY 2007-2009

from Mouginot, J., B. Scheuchl, and E. Rignot. (2017). MEaSUREs Antarctic Boundaries for IPY 2007-2009 from Satellite Radar, Version 2 [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/AXE4121732AD. accessed at https://nsidc.org/data/nsidc-0709/versions/2

Parameters:

version (str,) – choose which file to retrieve from the following list: “Coastline”, “Basins_Antarctica”, “Basins_IMBIE”, “IceBoundaries”, “IceShelf”, “Mask”

Returns:

file path

Return type:

str

modis_moa(version='750m')

Load the MODIS MoA imagery in either “750m” or “125m” resolutions.

Parameters:

version (str, optional) – choose between “750m” or “125m” resolutions, by default “750m”

Returns:

filepath for either 750m or 125m MODIS MoA Imagery

Return type:

str

moho(version, region=None, spacing=None, registration=None)

Load 1 of x ‘versions’ of Antarctic Moho depth grids.

version=’shen-2018’ Depth to the Moho relative to the surface of solid earth (bottom of ice/ocean) from Shen et al. 2018: The crust and upper mantle structure of central and West Antarctica from Bayesian inversion of Rayleigh wave and receiver functions. https://doi.org/10.1029/2017JB015346 Accessed from https://sites.google.com/view/weisen/research-products?authuser=0 Appears to be almost identical to crustal thickness from Shen et al. 2018

version=’an-2015’ This is fetch.crustal_thickness(version=’an-2015)* -1 Documentation is unclear whether the An crust model is crustal thickness or moho depths, or whether it makes a big enough difference to matter.

version=’pappa-2019’ from Pappa, F., Ebbing, J., & Ferraccioli, F. (2019). Moho depths of Antarctica: Comparison of seismic, gravity, and isostatic results. Geochemistry, Geophysics, Geosystems, 20, 1629- 1645. https://doi.org/10.1029/2018GC008111 Accessed from supplement material

Parameters:

• version (str) – Either ‘shen-2018’, ‘an-2015’, ‘pappa-2019’, will add later: ‘lamb-2020’, ‘baranov’, ‘chaput’, ‘crust1’, ‘szwillus’, ‘llubes’,

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

• spacing (int, optional) – grid spacing to resample the loaded grid to, by default spacing is read from downloaded files

• registration (str | None) –

Returns:

Returns a loaded, and optional clip/resampled grid of crustal thickness.

Return type:

xr.DataArray

rema(version='1km', region=None, spacing=None, registration=None)

Load the REMA surface elevation data. The data are in EPSG3031 and reference to the WGS84 ellipsoid. To convert the data to be geoid-referenced, subtract a geoid model, which you can get from fetch.geoid().

Choose between “1km” or “500m” resolutions with parameter version.

from Howat et al. 2019: The Reference Elevation Model of Antarctica, The Cryosphere, 13, 665-674, https://doi.org/10.5194/tc-13-665-2019.

accessed from https://www.pgc.umn.edu/data/rema/

Parameters:

• version (str, optional,) – choose which resolution to fetch, either “1km” or “500m”, by default is “1km”

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

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

• registration (str | None) –

Returns:

Returns a loaded, and optional clip/resampled grid of the REMA DEM.

Return type:

xr.DataArray

resample_grid(grid, initial_spacing=None, initial_region=None, initial_registration=None, spacing=None, region=None, registration=None, **kwargs)

Resample a grid to a new spacing, region, and/or registration. Method of resampling depends on comparison with initial and supplied values for spacing, region, and registration. If initial values not supplied, will try and extract them from the grid.

Parameters:

• grid (str | xr.DataArray) – grid to resample

• initial_spacing (float | None, optional) – spacing of input grid, if known, by default None

• initial_region (tuple[float, float, float, float] | None, optional) – region of input grid, if known, by default None

• initial_registration (str | None, optional) – registration of input grid, if known, by default None

• spacing (float | None, optional) – new spacing for grid, by default None

• region (tuple[float, float, float, float] | None, optional) – new region for grid, by default None

• registration (str | None, optional) – new registration for grid, by default None

• kwargs (dict[str, str]) –

Returns:

grid, either resampled or same as original depending on inputs. If no resampling, and supplied grid is a filepath, returns filepath.

Return type:

str | xr.DataArray

rosetta_gravity(version='gravity')

Load either a shapefile of ROSETTA-ice flightlines, a dataframe of ROSETTA-Ice airborne gravity data over the Ross Ice Shelf, or a dataframe of ROSETTA-Ice density values from the density inversion. from Tinto et al. (2019). Ross Ice Shelf response to climate driven by the tectonic imprint on seafloor bathymetry. Nature Geoscience, 12( 6), 441- 449. https://doi.org/10.1038/s41561-019-0370-2 Accessed from https://www.usap-dc.org/view/project/p0010035 This is only data from the first 2 of the 3 field seasons. Columns: Line Number: The ROSETTA-Ice survey line number, >1000 are tie lines Latitude (degrees): Latitude decimal degrees WGS84 Longitude (degrees): Longitude decimal degrees WGS84 unixtime (seconds): The number of seconds that have elapsed since midnight (00:00:00 UTC) on January 1st, 1970 Height (meters): Height above WGS84 ellipsoid x (meters): Polar stereographic projected coordinates true to scale at 71° S y (meters): Polar stereographic projected coordinates true to scale at 71° S FAG_levelled (mGal): Levelled free air gravity

Parameters:

version (str, optional) –

Returns:

Returns a dataframe containing the gravity, density, or flightline data

Return type:

pd.DataFrame

rosetta_magnetics()

Load a dataframe of ROSETTA-Ice airborne magnetics data over the Ross Ice Shelf from Tinto et al. (2019). Ross Ice Shelf response to climate driven by the tectonic imprint on seafloor bathymetry. Nature Geoscience, 12( 6), 441- 449. https://doi.org/10.1038/s41561-019-0370-2 Accessed from https://www.usap-dc.org/view/project/p0010035 Columns: Line Number: The ROSETTA-Ice survey line number, >1000 are tie lines Latitude (degrees): Latitude decimal degrees WGS84 Longitude (degrees): Longitude decimal degrees WGS84 unixtime (seconds): The number of seconds that have elapsed since midnight (00:00:00 UTC) on January 1st, 1970 H_Ell (meters): Height above WGS84 ellipsoid x (meters): Polar stereographic projected coordinates true to scale at 71° S y (meters): Polar stereographic projected coordinates true to scale at 71° S Mag_anomaly (nT): magnetic anomaly

Returns:

Returns a dataframe containing the data

Return type:

pd.DataFrame

sample_shp(name)

Load the file path of sample shapefiles

Parameters:

name (str) – chose which sample shapefile to load, either ‘Disco_deep_transect’ or ‘Roosevelt_Island’

Returns:

file path as a string

Return type:

str

sediment_thickness(version, region=None, spacing=None, registration=None)

Load 1 of 4 ‘versions’ of sediment thickness data.

version=’ANTASed’ From Baranov A, Morelli A and Chuvaev A (2021) ANTASed; An Updated Sediment Model for Antarctica. Front. Earth Sci. 9:722699. doi: 10.3389/feart.2021.722699 Accessed from https://www.itpz-ran.ru/en/activity/current-projects/antased-a-new-sediment-model-for-antarctica/

version=’tankersley-2022’ From Tankersley, Matthew; Horgan, Huw J; Siddoway, Christine S; Caratori Tontini, Fabio; Tinto, Kirsty (2022): Basement topography and sediment thickness beneath Antarctica’s Ross Ice Shelf. Geophysical Research Letters. https://doi.org/10.1029/2021GL097371 Accessed from https://doi.pangaea.de/10.1594/PANGAEA.941238?format=html#download

version=’lindeque-2016’ From Lindeque, A et al. (2016): Preglacial to glacial sediment thickness grids for the Southern Pacific Margin of West Antarctica. Geochemistry, Geophysics, Geosystems, 17(10), 4276-4285. https://doi.org/10.1002/2016GC006401 Accessed from https://doi.pangaea.de/10.1594/PANGAEA.864906

version=’GlobSed’ From Straume, E. O., Gaina, C., Medvedev, S., Hochmuth, K., Gohl, K., Whittaker, J. M., et al. (2019). GlobSed: Updated total sediment thickness in the world’s oceans. Geochemistry, Geophysics, Geosystems, 20, 1756- 1772. https://doi.org/10.1029/2018GC008115 Accessed from https://ngdc.noaa.gov/mgg/sedthick/

Parameters:

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

• region (tuple[float, float, float, float], optional) – GMT-format region to clip the loaded grid to, by default doesn’t clip

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

• registration (str | None) –

Returns:

Returns a loaded, and optional clip/resampled grid of sediment thickness.

Return type:

xr.DataArray