Abstract. We present a
new digital elevation model (DEM) of the bed, with a 1 km gridding, of the
Weddell Sea (WS) sector of the West Antarctic Ice Sheet (WAIS). The DEM has a
total area of ∼ 125 000 km2 covering the Institute, Möller
and Foundation ice streams, as well as the Bungenstock ice rise. In
comparison with the Bedmap2 product, our DEM includes new aerogeophysical
datasets acquired by the Center for Remote Sensing of Ice Sheets (CReSIS)
through the NASA Operation IceBridge (OIB) program in 2012, 2014 and 2016. We
also improve bed elevation information from the single largest existing
dataset in the region, collected by the British Antarctic Survey (BAS)
Polarimetric radar Airborne Science Instrument (PASIN) in
2010–2011, from the relatively crude measurements determined in the field
for quality control purposes used in Bedmap2. While the gross form of the new
DEM is similar to Bedmap2, there are some notable differences. For example,
the position and size of a deep subglacial trough (∼ 2 km below sea
level) between the ice-sheet interior and the grounding line of the
Foundation Ice Stream have been redefined. From the revised DEM, we are able
to better derive the expected routing of basal water and, by comparison with
that calculated using Bedmap2, we are able to assess regions where hydraulic
flow is sensitive to change. Given the potential vulnerability of this sector
to ocean-induced melting at the grounding line, especially in light of the
improved definition of the Foundation Ice Stream trough, our revised DEM will
be of value to ice-sheet modelling in efforts to quantify future
glaciological changes in the region and, from this, the potential impact on
global sea level. The new 1 km bed elevation product of the WS
sector can be found at https://doi.org/10.5281/zenodo.1035488.
Deglacial history of the West Antarctic Ice Sheet in the Weddell Sea embayment: Constraints on past ice volume change: REPLY
