Glaciolgist Reinhard Drews' Be:Wise project, which earned him this year's InBev-Baillet Latour Antarctic Fellowship, will study the flow dynamics of the Roi Baudouin ice-shelf, which buttresses ice flow from East-Antarctica’s ice sheet. The project is expected to provide important insights into the rapid fluctuations of historical ice discharges, and provide data for improving capacity of ice-flow models, in order to better forecast the balance of the Antarctic ice sheet mass balance in a warming world.
The project consists of two four-week long field campaigns on the Roi Baudouin ice shelf during two Antarctic seasons, starting in November 2012, where Be:Wise will examine the ice-dynamical role of grounded features, which are enclosed by the ice shelf, and which buttress the ice flow from the East-Antarctic ice sheet. Since almost three quarters of the Antarctic ice sheet boundary is in contact with the ocean, this case study is expected to contribute to the overall understanding of the Antarctic mass balance.
The Roi Baudouin ice shelf is confined by two ice rises with a local flow regime, and two pinning-points with a width of only a few kilometres; the latter seems to define the seaward edge of the ice shelf and impact ice-flow in the hinterland.
The project aims to investigate the connection between the flow-dynamics of the ice shelf with the locally grounded counterparts, by combining satellite remote sensing with on-site ground-penetrating radar and GPS measurements. The project also envisages geophysical parameters such as strain-rates, internal ice properties, surface velocities and characteristics of the bedrock interface. Preliminary studies indicate that the pinning-points of the Roi Baudouin ice shelf become partially afloat during high tide. Therefore, satellite images can be analysed which directly measure the effect of a de- and re-attachment from an ice shelf to a pinning point. This, and the proximity to the Princess Elisabeth station which enables on-site field measurements, make the Roi Baudouin ice shelf a unique field site for a case study, as it delivers important insight into the operation of the buttressing effect.
Larger-scale effect of ice-shelf buttressing, in terms of grounding-line migration and/or in terms of controlling the mass flux from the grounded ice sheet, are not fully understood. However, since the contact area between the ice shelf and local highs in bedrock elevation is susceptible to changing ocean characteristics, it is important to quantify this buttressing effect, in order to evaluate whether or not it is a key to understand rapid (~ centennial ) variations in ice-sheet geometry.
Since the ice-sheet mass balance is tightly linked to the overall sea level, this will help to better explain sea-level variations in the past and eventually contribute to forecasting the sea level rise in a warming world.