New Insights in the Existence of Lakes Beneath the Recovery Glacier Drainage Basin, Antarctica

Abstract:

The Recovery Glacier is draining about 8% of the East Antarctic ice sheet and feeds into the Filchner Ice Shelf. There were suggestions that the dynamics of the glacier is driven by large subglacial lakes that initiate the ice stream flow (Bell et al., 2008). As the Recovery Glacier is one of the least surveyed ice streams due to its remote location, this hypothesis could not be tested rigorously so far. In austral summer 2013/14 AWI carried out a survey of the Recovery Glacier including radio echo sounding, gravimetry, magnetics, and laser scanner. In total more than 22000 km survey lines were flown.

Here we present an ice thickness map of the main trunk of the Recovery Glacier, as well as its tributaries Blackwall and Ramp glaciers. The ice thickness varies between 70 m in the vicinity of the Shackleton Range and nearly 3800 m close to the Bell lakes.

Using different DEMs including one CryoSat-2 DEM (Helm et al., 2014), we determine the basal topography and the hydraulic head.

We estimate the basal reflection coefficient and assess by this locations with potentially wet ice base. The distribution shows that few of the formerly proposed lakes show indeed a wet base, while others are missing clear lake like basal reflections.