|Details1:||WHEN THE ANTARCTIC WAS WARMER THAN TODAY|
Quaternary Research. Volume 64, Issue 1 , July 2005, Pages 83-99
Late Quaternary climate-driven environmental change in the Larsemann Hills, East Antarctica, multi-proxy evidence from a lake sediment core
Dominic A. Hodgsona, , , Elie Verleyenb, Koen Sabbeb, Angela H. Squierc, Brendan J. Keelyc, Melanie J. Lengd, Krystyna M. Saunderse and Wim Vyvermanb
a) British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
b) Lab. Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281-S8, Ghent B-9000, Belgium
c) Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
d) Natural Environment Research Council, Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
e) Institute of Antarctic and Southern Ocean Studies, University of Tasmania, Private Bag 77, Hobart, TAS 7001, Australia
Little is known about the response of terrestrial East Antarctica to climate changes during the last glacial-interglacial cycle. Here we present a continuous sediment record from a lake in the Larsemann Hills, situated on a peninsula believed to have been ice-free for at least 40,000 yr. A mutli-proxy data set including geochronology, diatoms, pigments and carbonate stable isotopes indicates warmer and wetter conditions than present in the early part of the record. We interpret this as Marine Isotope Stage 5e after application of a chronological age-depth model and similar ice core evidence. Dry and cold conditions are inferred during the last glacial, with lake-level minima, floristic changes towards a shallow water algal community, and a greater biological receipt of ultraviolet radiation. During the Last Glacial Maximum and Termination I the lake was perennially ice-covered, with minimal snowmelt in the catchment. After ca. 10,500 cal yr B.P., the lake became seasonally moated or ice-free during summer. Despite a low accumulation rate, the sediments document some Holocene environmental changes including neoglacial cooling after ca. 2450 cal yr B.P., and a gradual increase in aridity and salinity to the present.
FULL PAPER at: http://tinyurl.com/7d5d6
Copyright © 2005 University of Washington Published by Elsevier Inc.
Bitte auf den Link clicken !