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Evidence for a large surface ablation zone in central East Antarctica during the last Ice Age

Published online by Cambridge University Press:  20 January 2017

Martin J. Siegert ,
Richard C. A. Hindmarsh  and
Gordon S. Hamilton
Martin J. Siegert*
Affiliation:
Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK
Richard C. A. Hindmarsh
Affiliation:
Physical Sciences Division, British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
Gordon S. Hamilton
Affiliation:
Institute for Quaternary and Climate Studies, and Department of Geological Sciences, University of Maine, 303 Global Sciences Center, Orono, ME 04469-5790, USA
*
*Corresponding author. Fax: +44-117-928-7878. E-mail address: [email protected] (M.J. Siegert).
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Abstract

Internal isochronous ice sheet layers, recorded by airborne ice-penetrating radar, were measured along an ice flowline across a large (>1 km high) subglacial hill in the foreground of the Transantarctic Mountains. The layers, dated through an existing stratigraphic link with the Vostok ice core, converge with the ice surface as ice flows over the hill without noticeable change to their separation with each other or the ice base. A two-dimensional ice flow model that calculates isochrons and particle flowpaths and accounts for ice flow over the hill under steady-state conditions requires net ablation (via sublimation) over the stoss face for the predicted isochrons to match the measured internal layers. Satellite remote sensing data show no sign of exposed ancient ice at this site, however. Given the lack of exposed glacial ice, surface balance conditions must have changed recently from the net ablation that is predicted at this site for the last 85,000 years to accumulation.

Type
Articles
Information
Quaternary Research , Volume 59 , Issue 1 , January 2003 , pp. 114 - 121
Copyright
Elsevier Science (USA)

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References

Bintanja, R. On the glaciological, meteorological, and climatological significance of Antarctic blue ice areas. Reviews of Geophysics 37, (1999). 337 359.CrossRefGoogle Scholar
Cresswell, R.G. Meteorite concentrations in Antarctica. Sites of katabatic wind ablation?. Geophysical Research Letters 15, (1988). 342 345.CrossRefGoogle Scholar
Drewry, D. J., (1983). Antarctica: Glaciological and Geophysical Folio. Scott Polar Research Institute, University of Cambridge.Google Scholar
Fujita, S., Maeno, H., Uratsuka, S., Furukawa, T., Mae, S., Fujii, Y., and Watanabe, O. Nature of radio-echo layering in the Antarctic ice sheet detected by a two-frequency experiment. Journal of Geophysical Research 104, B6 (1999). 13013 13124.Google Scholar
Glen, J.W. The creep of polycrystalline ice. Proceedings of the Royal Society of London A228, (1955). 519 538.Google Scholar
Gow, A.J., and Rowland, R. On the relationship of snow accumulation to surface topography at Byrd Station, Antarctica. Journal of Glaciology 5, (1965). 843 847.Google Scholar
Hindmarsh, R.C.A., (2001). Notes on basic glaciological computational methods and algorithms. in: Greve, R., Ehrentraut, Y., Wang, , Straughan, B. (Eds.), Continuum Mechanics in Geophysics and the Environment, Springer-Verlag, Berlin/New York.Google Scholar
Hindmarsh, R.C.A., and Hutter, K. Numerical fixed domain mapping solution Of free-surface flows coupled with an evolving interior field. Int J Numer Anal Met 12, 4 (1988). 437 459.Google Scholar
Lythe, M.B., Vaughan, D.G., the BEDMAP consortium. (2000). BEDMAP — Bed topography of the Antarctic. 1:10,000,000 map. BAS (Misc.) International Journal for Numerical and Analytical Methods in Geomechanics. 9, . Cambridge.Google Scholar
Parish, T.R. Surface winds over the Antarctic continent. A review. Reviews of Geophysics 26, (1988). 169 180.CrossRefGoogle Scholar
Parish, T.R., and Bromwich, D.H. The surface windfield over the Antarctic ice sheets. Nature 328, (1987). 51 54.Google Scholar
Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, J.M., Basile, I., Benders, M., Chappellaz, J., Davis, M., Delaygue, G., Delmotte, M., Kotlyakov, V.M., Legrand, M., Lipenkov, V.Y., Lorius, C., Pepin, L., Ritz, C., Saltzman, E., and Stievenard, M. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399, (1999). 429 436.Google Scholar
Reeh, N., Oerter, H., Letreguilly, A., Miller, H., and Hubberten, H.W. A new, detailed ice age oxygen 18 record from the ice sheet margin in Central West Greenland. Palaeogeography, Palaeoclimatology, Palaeoecology (Global and Planetary Change Section) 90, (1991). 373 383.Google Scholar
Siegert, M.J., and Fujita, S. Internal ice-sheet radar layer profiles and their relation to reflection mechanisms between Dome C and the Trans Antarctic Mountains. Journal of Glaciology 47, (2001). 205 212.Google Scholar
Siegert, M.J., and Hodgkins, R. A stratigraphic link across 1100 km of the Antarctic Ice Sheet between the Vostok ice core site and Titan Dome (near South Pole). Geophysical Research Letters 27, (2000). 2133 2136.Google Scholar
Siegert, M.J., Hodgkins, R., and Dowdeswell, J.A. A chronology for the Dome C deep ice-core site through radio-echo layer correlation with the Vostok ice core, Antarctica. Geophysical Research Letters 25, (1998). 1019 1022.CrossRefGoogle Scholar
Vaughan, D.G., Corr, H.F.J., Doake, C.S.M., and Waddington, E.D. Distortion of isochronous layers in ice revealed by ground-penetrating radar. Nature 298, (1999). 323 326.Google Scholar
Watanabe, O., (1997). Antarctica: East Queen Maud Land - Enderby Land Glaciological Folio. National Institute of Polar Research, Japan.Google Scholar
Whillans, I.M. Effect of inversion winds on topographic detail and mass balance on inland ice sheets. Journal of Glaciology 14, 70 (1975). 85 90.Google Scholar
Winther, J.-G., Jespersen, M.N., and Liston, G.E. Blue-ice areas in Antarctica derived from NOAA AVHRR satellite data. Journal of Glaciology 47, (2001). 325 334.Google Scholar