Accumulation and proxy-temperature variability in Dronning Maud Land, Antarctica, determined from shallow firn cores

Annals of Glaciology, Vol. 29, p. 17-22, 1999

E. Isaksson, J.-G. Winther
Norwegian Polar Institute, N-9296 Tromsø, Norway.
M.R. van den Broeke
Institute for Marine and Atmospheric Research, Utrecht University, P.O. Box 80005, 3508 TA Utrecht, The Netherlands.
L. Karlöf
Department of Physical Geography, Stockholm University, S-10691 Stockholm, Sweden.
J.F. Pinglot
Laboratoire de Glaciologie et Géophysique de l'Environnement du CNRS, BP 96, 38402 Saint-Martin-d'Hères Cedex, France.
N. Gundestrup
Departement of Geophysics, The Niels Bohr Institute of Astronomy, Physics and Geophysics, University of Copenhagen.

ABSTRACT.
During 1996-97 a European Project for Ice Coring in Antarctica (EPICA) pre-site surveying traverse worked in the area between 70^oS, 5^oE and 75^oS, 15^oE in Dronning Maud Land. We present data obtained from 10 and 20 m deep firn cores drilled between the coast and 600 km inland (to 3450 m a.s.l.). The cores were analyzed for electrical conductivity measurements and total ß activity to obtain accumulation data between known time horizons. In addition, some of the cores were analyzed for oxygen isotopes. Annual accumulation varies from 271 mm w.e. at Fimbulisen to 24 mm w.e. at 2840 m a.s.l. Accumulation at core sites 2400-3000 m a.s.l. has increased by 16-48% since 1965 compared to the 1955-65 period. However, the core sites above 3250 m a.s.l. and one core location on the ice shelf show a decrease during the same period. Furthermore, no change can be detected at the most inland site for the period 1815-1996. In all the cores the last few years seem to have been some of the warmest in these records.