DOI: 10.7280/d11q17
title: Ice thickness and bed elevation of the Northern and Southern Patagonian Icefields

description: The Northern and Southern Patagonian Icefields are the largest ice masses
 in the Southern Hemisphere outside Antarctica, but their ice volume and
 bed topography are poorly known. We combine airborne gravity data
 collected in 2012 and 2016, with radar data from the Warm Ice Experiment
 Sounder and Centro de Estudios Científicos's from year 2014 and 1015
 to map bed elevation and ice thickness in great detail. We perform a 3-D
 inversion of the gravity data constrained by radar-derived thickness and
 fjord bathymetry to infer bed elevation at 500-m spacing, with a precision
 of about 60 m. We detect deep glacial valleys with ice thickness exceeding
 1,400 m and sectors below sea level on the western branch of Glaciar Pio
 XI, Occidental, between San Rafael and Colonia, and near Fitz Roy. We
 calculate an ice volume of 4,756 ± 923 cubic kilometers for
 Northern Patagonia Icefield and Southern Patagonia Icefield, or 40 times
 the volume of glaciers in the European Alps. We perform a three
 dimensional inversion of the gravity field constrained by radar-derived
 thickness, ice boundary, and fjord bathymetry to infer bed elevation at
 500-m spacing, with a precision of about 50 m. The enclosed netCDF
 contains the following fields: X: x UTM coordinate
 (meters), Y: y UTM coordinate (meters), bed: bedrock
 elevation (meters), misfit: Misfit after inversion (calculated
 minus observed gravity), misfitm: Converted misfit using a
 conversion factor of 5.8 mGal per 100m, Source: Data source,
 0=bathymetry , 1=gravity, 2=radar depth sounder, and Fulthick:
 Comprehensive Ice thickness calculated using gravity inversion inside the
 survey domain and Carrivick 2016 modified outside. The projection is given
 as: "PROJCS[\"WGS 84 / UTM zone 18S\",GEOGCS[\"WGS
 84\",DATUM[\"WGS_1984\",SPHEROID[\"WGS84\",6378137,298.257223563,AUTHORITY[\"EPSG\",\"7030\"]],AUTHORITY[\"EPSG\",\"6326\"]], PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.0174532925199433,AUTHORITY[\"EPSG\",\"9122\"]],AUTHORITY[\"EPSG\",\"4326\"]], PROJECTION[\"Transverse_Mercator\"],PARAMETER[\"latitude_of_origin\",0],PARAMETER[\"central_meridian\",-75],PARAMETER[\"scale_factor\",0.9996],PARAMETER[\"false_easting\",500000],PARAMETER[\"false_northing\",10000000],UNIT[\"metre\",1,AUTHORITY[\"EPSG\",\"9001\"]],AXIS[\"Easting\",EAST],AXIS[\"Northing\",NORTH],AUTHORITY[\"EPSG\",\"32718\"]]"; More details in:  Millan, R., Rignot, E., Rivera, A., Martineau, V., Mouginot, J., Zamora, R., et al. (2019). Ice thickness and bed elevation of the Northern and Southern Patagonian Icefields. Geophysical Research Letters, 46, 6626–6635. https://doi.org/10.1029/ 2019GL082485 We also provide shape files of the radar thickness data collected by the NASA/JPL/UCI Warm Ice Sounding Experiment (WISE) in 2014 onboard a fixed-wing airfract and data collected by the CECS radar sounder, Dr. Andres Rivera, PI, on an helicopter.  For the WISE radar, bed returns were digitized manually and classified with a quality flag that reflected the uncertainty of identification of the bed: Quality 0 = 100 m, 1 = 50 m, and 2 = 25 m. Bed_WISE_20170726_utm18S: Complete data set of bed elevation above mean sea level. Bed_WISE_20170726_Quality0_utm18s: Quality 0. Bed_WISE_20170726_Quality1_utm18s: Quality 1. Bed_WISE_20170726_Quality2_utm18s: Quality 2. For the Rivera data, we do not provide quality labels. Bed_AndresRivera: All bed elevation above mean sea level. The projection is given as : PROJCS["WGS 84 / UTM zone 18S",GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-75],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",10000000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","32718"]].
description: # Ice thickness and bed elevation of the Northern and Southern Patagonian
 Icefields Dataset DOI: [10.7280/D11Q17](10.7280/D11Q17) ## Description of
 the data and file structure ### Repository Content: 1.
 GravBed_Patagonia_Millan_et_al_2019_v1.nc: Map of bed elevation in meters
 above mean seal level of the Patagonia Icefields. Projection: UTM 18
 South. Resolution: 150 m. Data format: GeoTIFF. Data type: Float32. NoData
 value: -9999. 2. Bed_WISE_20170726_Quality0_utm18s: ESRI shape file of bed
 elevation in meters below sea level from the WISE radar with quality
 0. Data format: ESRI shapefile format; ; Coordinate Reference System:
 EPSG:32718 WGS 84 UTM 18S 3. Bed_WISE_20170726_Quality1_utm18s: ESRI shape
 file of bed elevation in meters below sea level from the WISE radar with
 quality 1. Data format: ESRI shapefile format; ; Coordinate Reference
 System: EPSG:32718 WGS 84 UTM 18S 4.
 Bed_WISE_20170726_Quality2_utm18s: ESRI shape file of bed elevation in
 meters below sea level from the WISE radar with quality 2. Data format:
 ESRI shapefile format; ; Coordinate Reference System: EPSG:32718 WGS 84
 UTM 18S 5. Bed_WISE_20170726_utm18S : ESRI shape file of bed elevation in
 meters below sea level from the WISE radar. Data format: ESRI shapefile
 format; ; Coordinate Reference System: EPSG:32718 WGS 84 UTM 18S 6.
 Bed_AndresRivera: ESRI shape file of bed elevation in meters below sea
 level from the CECS radar. Data format: ESRI shapefile format; ;
 Coordinate Reference System: EPSG:32718 WGS 84 UTM 18S. Includes x, y, bed
 elevation, thickness, and surface elevation in meters above sea level. 
 ### Files and variables #### File:
 GravBed\_Patagonia\_Millan\_et\_al\_2019\_v1.nc **Description:** Map of
 bed elevation in meters above mean seal level of the Patagonia Icefields.
 Projection: UTM 18 South. Resolution: 150 m. Data format: GeoTIFF. Data
 type: Float32. NoData value: -9999. This netCDF contains the following
 fields: \- X: x UTM coordinate (meters) -Y: y UTM coordinate (meters)
 -bed: bedrock elevation (meters) -misfit: Misfit after inversion
 (calculated minus observed gravity) -misfitm: Converted misfit using a
 conversion factor of 5.8 mGal per 100m -Source: Data source, 0=bathymetry
 , 1=gravity, 2=radar depth sounder -Fulthick: Comprehensive Ice thickness
 calculated using gravity inversion inside the survey domain and Carrivick
 2016 modified outside. More details in:  Millan, R., Rignot, E., Rivera,
 A., Martineau, V., Mouginot, J., Zamora, R., et al. (2019). Ice thickness
 and bed elevation of the Northern and Southern Patagonian Icefields.
 Geophysical Research Letters, 46, 6626–6635.
 [https://doi.org/10.1029/](https://doi.org/10.1029/) 2019GL082485 ####
 File: Bed\_WISE\_20170726\_Quality0\_utm18s.shp **Description:** ESRI
 shape file of bed elevation in meters below sea level from the WISE radar
 with quality 0. Data format: ESRI shapefile format; ; Coordinate Reference
 System: EPSG:32718 WGS 84 UTM 18S #### File:
 Bed\_WISE\_20170726\_Quality1\_utm18s.shp **Description:** ESRI shape file
 of bed elevation in meters below sea level from the WISE radar with
 quality 1. Data format: ESRI shapefile format; ; Coordinate Reference
 System: EPSG:32718 WGS 84 UTM 18S #### File:
 Bed\_WISE\_20170726\_Quality2\_utm18s.shp **Description:** ESRI shape file
 of bed elevation in meters below sea level from the WISE radar with
 quality 2. Data format: ESRI shapefile format; ; Coordinate Reference
 System: EPSG:32718 WGS 84 UTM 18S #### File:
 Bed\_WISE\_20170726\_utm18S.shp **Description:** ESRI shape file of bed
 elevation in meters below sea level from the WISE radar. Data format: ESRI
 shapefile format; ; Coordinate Reference System: EPSG:32718 WGS 84 UTM 18S
 #### File: Bed\_AndresRivera.shp **Description:** SRI shape file of bed
 elevation in meters below sea level from the CECS radar. Data format: ESRI
 shapefile format; ; Coordinate Reference System: EPSG:32718 WGS 84 UTM
 18S. Includes x, y, bed elevation, thickness, and surface elevation in
 meters above sea level.