Ice thickness and bed elevation of the Northern and Southern Patagonian Icefields

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"]].