HR: 0800h
AN: C51A-0082    [Abstracts]
TI: Using new airborne gravity data to revisit uplift of the Transantarctic Mountains and to investigate the adjacent Wilkes Subglacial Basin beneath the East Antarctic Ice Sheet
AU: Moss, C
EM: ffe@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET, United Kingdom
AU: Jordan, T
EM: tomj@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET, United Kingdom
AU: * Ferraccioli, F
EM: ffe@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET, United Kingdom
AU: Watts, T
EM: Tony.Watts@earth.ox.ac.uk
AF: Department of Earth Sciences, University of Oxford, Park Road, Oxford, OX1 3PR, United Kingdom
AU: Armadillo, E
EM: egidio@dipteris.unige.it
AF: Dipartimento per lo Studio del Territorio e delle Sue Risorse, Viale Benedetto XV, 5, Genova, 16132, Italy
AU: Bozzo, E
EM: bozzo@dipteris.unige.it
AF: Dipartimento per lo Studio del Territorio e delle Sue Risorse, Viale Benedetto XV, 5, Genova, 16132, Italy
AU: Corr, H
EM: hfjc@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET, United Kingdom
AU: Caneva, G
EM: caneva@dipteris.unige.it
AF: Dipartimento per lo Studio del Territorio e delle Sue Risorse, Viale Benedetto XV, 5, Genova, 16132, Italy
AB: The Transantarctic Mountains (TAM) are the highest and longest rift-related Cenozoic mountain range of our planet. Models for the evolution of the East Antarctic Ice Sheet (EAIS) state that, during post-late Eocene cooling local glaciers and ice caps nucleated on the highlands of the East Antarctic craton, including the proto-TAM. These ice caps expanded and then merged during major climatic Neogene cooling events. Differential Neogene uplift of TAM blocks has also been advocated as a possible way of reconciling opposing views of stabilists and dynamists for the EAIS during warm periods. The TAM are therefore a natural laboratory to study interplays between rifting, mountain uplift, ice sheets, landscape evolution and climate change. The rift basins adjacent to TAM front are relatively well understood, but less is known about the deep crustal structure and uplift mechanisms of the TAM rift flank, and even less is known about the enigmatic Wilkes Subglacial Basin (WSB) in the hinterland of the TAM. During the 2005/06 Antarctic field season a major collaborative UK-Italian aerogeophysical survey was flown linking the Ross Sea Rift basins offshore with the TAM and the WSB. 60,000 line km of new airborne radar, aerogravity and aeromagnetic data were collected. New Free-Air gravity, Bouguer gravity and isostatic residual maps will be presented. The Free-Air gravity map reveals several linear lows and highs within this part of the WSB adjacent to northern Victoria Land, consistent with airborne radar evidence for previously unrecognised deep trenches and highland blocks in the hinterland of the TAM. To model TAM uplift we will initially utilise gravity and topography data over a relatively low elevation block further south along the TAM, the Prince Albert Mountains. Here independent wide-angle seismic data are available onshore, and relative proximity to the Cape Roberts drilling site offshore provides some information on timing of rifting, magnitude of TAM uplift, and climate evolution.
DE: 0726 Ice sheets
DE: 1219 Gravity anomalies and Earth structure (0920, 7205, 7240)
DE: 8109 Continental tectonics: extensional (0905)
DE: 8138 Lithospheric flexure
DE: 8177 Tectonics and climatic interactions
SC: Cryosphere [C]
MN: 2007 Fall Meeting