Geographic provenance of aeolian dust in East Antarctica during Pleistocene glaciations: preliminary results from Talos Dome and comparison with East Antarctic and new Andean ice core data

Links between Patagonian Ice Sheet fluctuations and Antarctic dust variability during the last glacial period (MIS 4-2)

“…Furthermore, the isotopic signature of last glacial clays and silts from southern Patagonia is consistent with values of glacial dust from Antarctic ice cores (Sugden et al, 2009) and He isotopic signatures of mineral dust in Antarctica suggest an increased weathering flux in Patagonia during glacial times (Winckler and Fischer, 2009). Finally, recent studies suggest that a second dust source end-member may be located on the high subtropical Andean plateaus (Puna-Altiplano area, 10 e26 S) (Gaiero, 2007;Delmonte et al, 2010). Sugden et al (2009) could show that dust peaks in Antarctica coincide with periods in Patagonia when rivers fed by glacial meltwater deposited sediment onto outwash plains, while no dust peaks were noted when the glaciers terminated into proglacial lakes.…”

“…In turn, the higher ice-surface altitude linked to PIS growth would not only further increase precipitation on the western side of the Andes by enhancing the orographic rise of moist Pacific air masses, but also favour foehn winds on the lee side of the Andes, which would intensify aridity and increase dust mobilization in the southern Pampas and Patagonia (Prieto, 1996;Hulton et al, 2002;Gaiero, 2007). Data suggest that the dust source area extended at least until 37 S during MIS 2 (Smith et al, 2003), and maybe even further north (Gaiero, 2007;Delmonte et al, 2010). The dust source area extended probably also further south and east of its present-day southern limit as a lowered sea-level would increase the Argentine continental shelf area (see section 4.3).…”

Interpreting last glacial to Holocene dust changes at Talos Dome (East Antarctica): implications for atmospheric variations from regional to hemispheric scales

“…Previous work has shown that dust deposition at TALDICE responded to large climate variations on glacialinterglacial time scales, similar to the CEAP sites, with higher fluxes during cold stages (Delmonte et al, 2010b), when TALDICE and CEAP sites had a similar dust isotopic composition, suggesting common dust sources (Delmonte et al, 2010a). On the other hand, a different dust isotopic composition between TALDICE and CEAP sites during the Holocene, together with the presence of dust grains larger than 5 µm (diameter) that were virtually absent in the EDC core, highlight the significant contribution of dust of local origins to the TALDICE dust content (Delmonte et al, 2010b).…”

“…In this work, we present and analyze a higher resolution dust record, and in light of previous works (Delmonte et al, 2010a, b), we carry out a closer inspection of dust flux and grain size variability with respect to the TALDICE stable water isotopes (δ 18 O) profile, and compare this profile to EDC, which is assumed to be representative of CEAP sites. In this (Conway et al, 1999;Hall, 2009). comparative dust-δ 18 O Talos Dome versus CEAP analysis throughout the deglaciation and the Holocene, we explore possible links between dust sources, atmospheric variations and the deglaciation history of the Ross Sea embayment.…”

Periodic 1.5 ka climate variations during MIS 2 in the belt of Southern Hemispheric westerlies

“…This hypothesis is supported by data from geochemical fingerprinting (Grousset et al, 1992;Basile et al, 1997;Gaiero, 2007;Sugden et al, 2009;Delmonte et al, 2010).…”