Bed topography of Princess Elizabeth Land in East Antarctica

Xiangbin Cui,Lin Li,Laura E Lindzey,Wei Wei,Feras A Habbal,Martin J Siegert,Jamin S Greenbaum,Sun Bo,Hafeez Jeofry,Lenneke M Jong,Jason L Roberts,Jingxue Guo,Duncan A Young,Mathieu Morlighem,Donald D Blankenship,Neil Ross

doi:10.5194/essd-12-2765-2020

Abstract

Abstract. We present a topographic digital elevation model (DEM) for Princess Elizabeth Land (PEL), East Antarctica. The DEM covers an area of ∼900 000 km2 and was built from radio-echo sounding data collected during four campaigns since 2015. Previously, to generate the Bedmap2 topographic product, PEL's bed was characterized from low-resolution satellite gravity data across an otherwise large (>200 km wide) data-free zone. We use the mass conservation (MC) method to produce an ice thickness grid across faster flowing (>30 m yr−1) regions of the ice sheet and streamline diffusion in slower flowing areas. The resulting ice thickness model is integrated with an ice surface model to build the bed DEM. Together with BedMachine Antarctica and Bedmap2, this new bed DEM completes the first-order measurement of subglacial continental Antarctica – an international mission that began around 70 years ago. The ice thickness data and bed DEMs of PEL (resolved horizontally at 500 m relative to ice surface elevations obtained from the Reference Elevation Model of Antarctica – REMA) are accessible from https://doi.org/10.5281/zenodo.4023343 (Cui et al., 2020a) and https://doi.org/10.5281/zenodo.4023393 (Cui et al., 2020b).

Highlights

Radio-echo sounding (RES) is commonly used to measure ice thickness and to understand subglacial topography and basal ice sheet conditions (Dowdeswell and Evans, 2004; Bingham and Siegert, 2007)
We present a topographic digital elevation model (DEM) for Princess Elizabeth Land (PEL), East Antarctica
A series of airborne geophysical explorations were conducted across East Antarctica in the 1970s (Robin et al, 1977; Dean et al, 2008; Turchetti et al, 2008; Naylor et al, 2008), which led to the first compilation folio of maps of subglacial bed topography, ice sheet surface elevation, and ice thickness in Antarctica (Drewry and Meldrum, 1978; Drewry et al, 1980; Jankowski and Drewry, 1981; Drewry, 1983)

Summary

Introduction

Radio-echo sounding (RES) is commonly used to measure ice thickness and to understand subglacial topography and basal ice sheet conditions (Dowdeswell and Evans, 2004; Bingham and Siegert, 2007). Virtually no RES data had been acquired upstream of ∼ 300 km from the grounding line of PEL, . This region has been described as one of the so-called “poles of ignorance” (Fretwell et al, 2013), and its representation in recent bed DEMs (e.g., Bedmap and BedMachine Antarctica) is as a zone of flat topography, reflecting the absence of data (Morlighem et al, 2020). We present the first detailed ice thickness DEM for PEL, based on new RES measurements collected since 2015, which we refer to as the ICECAP2 DEM. The ice thickness DEM can be integrated with updated surface DEMs (i.e. Helm et al, 2014) and, in particular, the upcoming Bedmap product

Study area

Data and methods

Data processing

Subglacial morphology of Princess Elizabeth Land

Comparison with Bedmap2 and BedMachine Antarctica

Summary