TALOS Dome Migration: Preliminary Results

Ice divide-dome migration is a key parameter in mass balance studies and in the interpretation of ice cores. The stability of the dome and position of the ice divide must be known to accurately interpret ice core records and to complete mass balance studies. Models of depth-age relationships for deep ice cores are sensitive to migration of the dome position (Anandakrishnan et al., 1994). The evolution of an ice divide is driven by the accumulation-rate history, its spatial pattern and conditions at ice-sheet boundaries (e.g. Frezzotti et al., 2004; Hindmarsh, 1996; Nereson et al., 1998). Ice divide migration is also important in determining the input parameter of large Antarctic drainage basins. Due to the very low slope (less than a decimetre per km) of East Antarctic domes and to surface morphology (e.g. sastrugi), it is very difficult to determine the summit point of a dome and its migration in time. In 2004 a new ice coring project, TALDICE (Talos Dome Ice
Core Project), started at TD to recover 1550 m of ice spanning the last 120 000 years (Frezzotti et al., 2004). This paper discusses preliminary findings on the present and past morphology of Talos Dome based on detailed snow accumulation data, radar-derived isochrons and ice velocity measurements in the last 10 years.

Anandakrishnan S., R.B. Alley & E.D. Waddington, 1994. Sensitivity of the ice-divide position in Greenland
to climate change. Geophys. Res. Lett., 21(6) 441-444.
Frezzotti M., G. Bitelli, P. de Michelis, A. Deponti, A. Forieri, S. Gandolfi, V. Maggi, F. Mancini, F. Rémy,
I.E. Tabacco, S. Urbini, L. Vittuari & A. Zirizzotti, 2004. Geophysical survey at Talos Dôme (East
Antarctica): The search for a new deep-drilling site. Ann. Glaciol., 39, 423-432.
Frezzotti M., S. Gandolfi & S. Urbini, 2002. Snow megadunes in Antarctica: sedimentary structure and
genesis. J. Geoph. Res., 107(D18), 4344, 10.1029/2001JD000673, 1-12.
Frezzotti M., M. Pourchet, O. Flora, S. Gandolfi, M. Gay, S. Urbini, C. Vincent, S. Becagli, R. Gragnani,
M. Proposito, M. Severi, R. Traversi, R. Udisti & M. Fily, 2005 Spatial and temporal variability of
snow accumulation in East Antarctica from traverse data. J. Glaciol., 51(207), 113-124.
Hindmarsh R.C.A., 1996. Stochastic perturbation of divide position. Ann. Glaciol., 23, 94-104.
Magand O., M. Frezzotti, M. Pourchet, B. Stenni, L. Genoni & M. Fily, 2004. Climate variability along
latitudinal and longitudinal transects in East Antarctica. Ann. Glaciol., 39, 351-358.
Nereson N.A, Raymond, C.F., Waddington, E.D. & R.W. Jacobel, 1998. Migration of the Siple Dome ice
divide, West Antarctica. J. Glaciol., 44(148), 643-652.
Richardson C., E. Aarholt, S.-E. Hamran, P. Holmlund & E. Isaksson, 1997. Spatial snow distribution of
snow in western Dronning Maud Land, East Antarctica, mapped by a ground based snow radar. J.
Geophys. Res., 102(B9), 20,343-20,353.
Stenni B., Proposito M., Gragnani R., Flora O., Jouzel J., Falourd S. & Frezzotti M., 2002. Eight centuries
of volcanic signal and climate change at Talos Dome (East Antarctica). J. Geoph. Res., D9, 107,
10.1029/2000JD000317, 1-14.
Vaughan D.G., H.J.F. Corr, C.S.M. Doake & E.D. Waddington, 1999. Distortion of isochronous layers in
ice revealed by ground-penetrating radar, Nature, 398 (6725), 323-326.