DOI: 10.5285/2d0e4791-8e20-46a3-80e4-f5f6716025d2
title: BEDMAP3 - Ice thickness, bed and surface elevation for Antarctica - gridding products

description: We present here Bedmap3, the latest suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of Antarctica south of 60degS. 
Bedmap3 incorporates and adds to all post-1950s datasets previously used for Bedmap1 and Bedmap2, including 84 new aero-geophysical surveys by 15 data providers, an additional 52 million data points and 1.9 million line-kilometres of measurement. This has filled notable gaps in East Antarctica, including the South Pole and Pensacola basin, Dronning Maud Land, Recovery Glacier and Dome Fuji, Princess Elizabeth Land, plus the Antarctic Peninsula, West Antarctic coastlines, and the Transantarctic Mountains. Our new Bedmap3/RINGS grounding line similarly consolidates multiple recent mappings into a single, spatially coherent feature. Combined with updated maps of surface topography, ice shelf thickness, rock outcrops and bathymetry, Bedmap3 reveals in much greater detail the subglacial landscape and distribution of Antarctica's ice, providing new opportunities to interpret continental-scale landscape evolution and to model in detail the past and future evolution of the Antarctic ice sheets.
Sponsored by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action group aims to produce a new map and datasets of Antarctic ice thickness and bed topography for the international scientific community.
The associated Bedmap datasets are listed here: https://www.bas.ac.uk/project/bedmap/#data
description: We created the Bedmap3 classification mask and grids of surface elevation, ice thickness, bed topography and uncertainty from a combination of new and existing interpolations of discontinuous survey datasets (airborne ice thickness, ship-borne bathymetry), existing gridded datasets from satellite-based mapping of rock outcrops, surface topography and ice shelf thickness, and a compilation of grounding zone coastal features extracted from satellite analysis. These outputs were created in the ArcGIS Pro software package. Specific details are provided in the associated paper (Prichard et al.)
description: All the grids have a cell size of 500m in the WGS 1984 Antarctic Polar Stereographic projection (EPSG:3031). Some specific quality control checks and corrections (e.g. negative height relative to sea level for 'sea' cells while 'non-sea' cells have positive values) have been undertaken and are extensively described in the associated paper (Pritchard et al.).
The uncertainty grids have been calculated through error budgets based upon a combination of published uncertainties and our own tests of accuracy and precision. The input datasets inherently have uncertainties with differing statistical distributions, and not all are well known. Furthermore, most Bedmap3 cells have values that are interpolated between sparse observations, and the uncertainties in this process are also difficult to quantify. Our uncertainties are therefore a best estimate based on the available evidence, given to approximately the 1-sigma level.