HR: 11:05h
AN: C42A-04    [Abstracts]
TI: Stable or dynamic(?) East Antarctic Ice Sheet during warm paleoclimates: new aerogeophysical perspectives
AU: * Ferraccioli, F
EM: ffe@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
AU: Corr, H
EM: hfjc@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
AU: Jordan, T
EM: tomj@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
AU: Armadillo, E
EM: egidio@dipteris.unige.it
AF: Dipartimento per lo Studio del Territorio e delle Sue Risorse, Univ. di Genova, Viale Benedetto XV, 5, Genova, 16322, Italy
AU: Hill, D
EM: dahi@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
AU: Hindmarsh, R
EM: rcah@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
AU: Haywood, A
EM: ahay@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
AU: Bozzo, E
EM: bozzo@dipteris.unige.it
AF: Dipartimento per lo Studio del Territorio e delle Sue Risorse, Univ. di Genova, Viale Benedetto XV, 5, Genova, 16322, Italy
AU: John, S
EM: jlsm@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
AU: Caneva, G
EM: caneva@dipteris.unige.it
AF: Dipartimento per lo Studio del Territorio e delle Sue Risorse, Univ. di Genova, Viale Benedetto XV, 5, Genova, 16322, Italy
AU: Robinson, C
EM: carob@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
AB: Boundary conditions for the East Antarctic Ice Sheet (EAIS) such as subglacial topography, subglacial hydrology, the distribution of subglacial sediments, heat flux, crustal thickness, lithosphere rigidity, and tectonic structures can assist predictive ice sheet modelling addressing its role for future sea-level change. One of the key areas to assess the past, present and future stability of the EAIS is the Wilkes Subglacial Basin (WSB), in the backside of the Transantarctic Mountains. Dynamists for the EAIS predict that significant deglaciation occurred perhaps as recently as the Pliocene, allowing for major marine incursion into the WSB. Conversely stabilists have argued that since at least 14 Ma there has been a relatively stable ice sheet. This debate remains highly timely since predictions of the response of the EAIS to current global warming could utilise its past response as a template for the future. A major collaborative UK-Italian aerogeophysical survey was flown over the WSB during the 2005/06 field season to provide new boundary conditions for the EAIS. Over 60,000 line km of new data were collected, including airborne radar, aeromagnetic and airborne gravity. Our new-sub-ice topography significantly changes the previous view of the WSB as a broad shallow depression. Deep subglacial trenches flanked by mountain blocks and plateau-like features are now imaged. These tectonically controlled trenches remain well below sea-level even after isostastic rebound following glacial removal, much like the deep basins underlying highly dynamic ice streams of the West Antarctic Ice Sheet. The newly determined subglacial topography will be input into preliminary coupled-ice sheet\paleoclimate models to re-assess the stability of the EAIS. We will also present potential field signatures and preliminary models to tackle the contentious issue of possible sedimentary infill beneath parts of the WSB.
DE: 0694 Instruments and techniques
DE: 0726 Ice sheets
DE: 0798 Modeling
DE: 0903 Computational methods: potential fields (1214)
DE: 1621 Cryospheric change (0776)
SC: Cryosphere [C]
MN: 2007 Fall Meeting