The Last Glacial Maximum and deglaciation in southern South America

Geochemistry of surface sediments from the fjords of Northern Chilean Patagonia (44–47°S): Spatial variability and implications for paleoclimate reconstructions

“…8). Similar low chemical weathering conditions are expected during the deglaciation (17-12 kyr BP; Hulton et al, 2002) since the climate was colder and glaciers were more expanded than during the Neoglaciation (~4500-1000 BP; Glasser et al, 2004). Although temperature was ~2ºC higher during the early Holocene (Heusser and Streeter, 1980;Glasser et al, 2004), this was likely not sufficient to significantly increase chemical weathering rates (Gislason et al, 2009), especially since precipitation decreased concomitantly (Heusser and Streeter, 1980).…”

A single Mid-Pleistocene long-distance dispersal by a bird can explain the extreme bipolar disjunction in crowberries ( Empetrum )

“…The Patagonian Andes and the eastern piedmont areas between 36°S and 56°S were almost completely covered by a continuous ice sheet, the Great Patagonian Glaciation (GPG), with ice tongues reaching the Atlantic coast south of Río Gallegos (~51°S) toward the end of the Early Pleistocene (20,21). The GPG was followed by four major glaciations (20) during the Middle and Late Pleistocene, the last having its maximum between 19,000 and 23,000 y ago (22). The upper age constraints for the end of the Danaglacial/post-GPG 1 (0.76 Ma) and the Gotiglacial/post-GPG 2 and 3 [0.065 Ma (20)] fit well with our estimated median ages for southern hemisphere Empetrum.…”

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

“…At a larger scale, modelled PIS snowlines are most sensitive to air temperature changes in regions of high precipitation (46 e50 S), and most sensitive to precipitation changes in regions of low precipitation (south of 50 S and north of 40 S) (Kerr and Sugden, 1994). In a modelling study of the PIS deglaciation, the NPIS is much more sensitive to climate forcing than the southern PIS (south of w48 S) and reacts rapidly to relatively small changes in both temperature and precipitation (Hulton et al, 2002). Furthermore, in their modelling study of the NPIS, Hubbard et al (2005) have shown that a weaker lowering of the equilibrium line altitude (ELA), which is a function of both air temperature and rainfall changes, results in glacier advances on the western part of the NPIS, while a stronger ELA lowering is necessary for glacier advances in its eastern part.…”