Structure, dynamics and stability of Antarctic ice shelves: field research
CfG staff: Bryn Hubbard
Key collaborators: Université Libre de Brussels; Norsk Polarinstitutt; Alfred Wegener Institut; Swansea University
Field-based research on ice shelves has focused, through campaigns in 2008, 2010 and 2012 (with another planned for 2014), on the Roi Baudouin Ice Shelf (RBIS) located on the Princess Ragnhild Coast of East Antarctica. This research is being undertaken in collaboration with colleagues from several European institutions and has been funded principally by the Belgian Federal Science Policy Office (BELSPO).
Research at the RBIS has combined ice coring and borehole drilling by hot water (Figure 1) with ice-surface radar to reveal the internal structure of various ice shelf terrains, including newly-formed ice present within the base of large rifts and contrasting accumulation patterns between the surface of the shelf proper and at the high-elevation Derwael Ice Rise (DIR). To date we have reported on (i) the variety of ice characteristics and types present within the shelf, including at least two forms of ‘marine ice’ forming at the base of the shelf and within rifts, (ii) zones of basal melting and refreezing as a result of oceanic circulation beneath the shelf, identified for the first time in this sector of Antarctica, and (iii) the application of borehole optical televiewing (Figure 2) as a proxy for the density of ice-shelf snow, firn and newly-formed ice.
Ongoing research focuses on high-resolution measurements of vertical strain within the ice shelf, the presence and record of pre- and post-industrial trace gas concentrations within the ice core records recovered, and contrasting accumulation and vertical strain rates between the shelf and the DIR.
Hubbard, B., Tison, J.-L., Philippe, M., Heene, B., Pattyn, F., Malone, T., Freitag, J. In review. Ice-shelf density reconstructed from optical-televiewer borehole logging. Geophysical Research Letters
Pattyn, F., Matsuoka, K., Callens, D., Conway, H., Depoorter, M., Docquier, D., Hubbard, B., Samyn, D. and Tison, J.-L. 2012. Melting and refreezing beneath Roi Baudouin Ice Shelf (East Antarctica) inferred from radar, GPS, and ice-core data. Journal of Geophysical Research - Earth Surface 117, F04008. doi: 10.1029/2011JF002154
Hubbard, B., Tison, J.-L., Pattyn, F., Dierckx, M., Boereboom, T. and Samyn, D. 2012. Optical televiewer-based identification and characterization of material facies associated with an Antarctic ice-shelf rift. Annals of Glaciology 53 (60), 137-146. doi: 10.3189/2012AoG60A045