Late Quaternary deglaciation and climate history of the Larsemann Hills (East Antarctica)

Abstract

The Late Quaternary climate history of the Larsemann Hills has been reconstructed using siliceous microfossils (diatoms, chrysophytes and silicoflagellates) in sediment cores extracted from three isolation lakes. Results show that the western peninsula, Stornes, and offshore islands were ice-covered between 30 000 yr BP and 13 500 cal. yr BP. From 13 500 cal. yr BP (shortly after the Antarctic Cold Reversal) the coastal lakes of the Larsemann Hills were deglaciated and biogenic sedimentation commenced. Between 13 500 and 11 500 cal. yr BP conditions were warmer and wetter than during the preceding glacial period, but still colder than today. From 11 500 to 9500 cal. yr BP there is evidence for wet and warm conditions, which probably is related to the early Holocene climate optimum, recorded in Antarctic ice cores. Between 9500 and 7400 cal. yr BP dry and cold conditions are inferred from high lake-water salinities, and low water levels and an extended duration of nearshore sea-ice. A second climate optimum occurred between 7400 and 5230 cal. yr BP when stratified, open water conditions during spring and summer characterised the marine coast of Prydz Bay. From 5230 until 2750 cal. yr BP sea-ice duration in Prydz Bay increased, with conditions similar to the present day. A short return to stratified, open water conditions and a reduction in nearshore winter sea-ice extent is evident between 2750 and 2200 cal. yr BP. Simultaneously, reconstructions of lake water depth and salinity suggests relatively humid and warm conditions on land between 3000 and 2000 cal. yr BP, which corresponds to a Holocene Hypsithermal reported elsewhere in Antarctica. Finally, dry conditions are recorded around 2000, between 760 and 690, and between 280 and 140 cal. yr BP. These data are consistent with ice-core records from Antarctica and support the hypothesis that lacustrine and marine sediments on land can be used to evaluate the effect of long-term climate change on the terrestrial environment.

Paleoenvironments of a proglacial lake in Schirmacher Oasis, East Antarctica: Insights from quartz grain microtextures

“…A previous study has also revealed that the Schirmacher Oasis was probably deglaciated at the Pleistocene-Holocene boundary (Gingele et al 1997). This phenomenon is almost similar to that in the Larsemann Hills where the lakes were ice-free during 11.5 and 9.5 ka BP (Verleyen et al 2003(Verleyen et al , 2004a(Verleyen et al , 2004bHodgson et al 2004). This rise in temperature can be correlated with the commencement of the Holocene warming in other East Antarctic oases (Ingόlfsson et al 1998;Gore et al 2001;Hodgson et al 2001;Kirkup et al 2002).…”

Ionic Characters of Lake Water of Bharti Promontory, Larsemann Hills, East Antarctica

“…Earlier studies focusing on environmental aspects of this region were carried out by Gillieson (1991), Hodgsn et al (2005), Verleyen et al (2004) and many other scientists. This presentation will highlight the different hydro-chemical aspects.…”

Glacial–interglacial climatic variations at the Schirmacher Oasis, East Antarctica: The first report from environmental magnetism

“…ka B.P. as suggested by the low lake levels (Verleyen et al, 2004). Lakes in the Bunger Hills were also covered by ice for an extended period, indicating cold and dry conditions with reduced melt-water input from 9 to 5.5 cal.…”