Was South Georgia covered by an ice cap during the Last Glacial Maximum?

2017 ◽  
Vol 461 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Duanne A. White ◽  
Ole Bennike ◽  
Martin Melles ◽  
Sonja Berg ◽  
Steven A. Binnie
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
South Georgia ◽  
Last Glacial ◽  
Ice Cap ◽  
The Last Glacial Maximum ◽  
The Last Glacial

New evidence for an independent Wisconsin-age ice cap over Newfoundland

1970 ◽  
Vol 7 (6) ◽  
pp. 1374-1382 ◽  
Author(s):  
Ian A. Brookes
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Ice Cap ◽  
Early View ◽  
New Evidence ◽  
The Last Glacial Maximum ◽  
The Last Glacial

A reinterpretation of the relative ages of glacial striae in southwestern Newfoundland, and new evidence from erratic till-boulder provenances there, support an early view, since abandoned, that at the last glacial maximum the island supported its own ice cap and was not affected by ice from Labrador.

Glacier Modeling and the Climate of Patagonia during the Last Glacial Maximum

1994 ◽  
Vol 42 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Nick Hulton ◽  
David Sugden ◽  
Antony Payne ◽  
Chalmers Clapperton
Keyword(s):  
Mass Balance ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Equilibrium Line Altitude ◽  
Last Glacial ◽  
Ice Cap ◽  
The Andes ◽  
The Antarctic ◽  
The Last Glacial Maximum ◽  
The Last Glacial

AbstractIce cap modeling constrained by empirical studies provides an effective way of reconstructing past climates. The former Patagonian ice sheet is in a climatically significant location since it lies athwart the Southern Hemisphere westerlies and responds to the latitudinal migration of climatic belts during glacial cycles. A numerical model of the Patagonian ice cap for the last glacial maximum (LGM) is developed, which is time-dependent and driven by changing the mass balance/altitude relationship. It relies on a vertically integrated continuity model of ice mass solved over a finite difference grid. The model is relatively insensitive to ice flow parameters but highly sensitive to mass balance. The climatic input is adjusted to produce the best fit with the known limits of the ice cap at the LGM. The ice cap extends 1800 km along the Andes and has a volume of 440,000 km3. During the LGM the equilibrium line altitude (ELA) was lower than at present by at least 560 m near latitude 40°S, 160 m near latitude 50°S, and 360 m near latitude 56°S. The latitudinal variation in ELA depression can be explained by an overall fall in temperature of about 3.0°C and the northward migration of precipitation belts by about 5° latitude. Annual precipitation totals may have decreased by about 0.7 m at latitude 50°S and increased by about 0.7 m at latitude 40°S. The ELA rises steeply by up to 4 m per kilometer from west to east as the westerlies cross the Andes and this prevents ice growth to the east. The limited decrease in temperature during the LGM could be related to the modest migration of the Antarctic convergence between South America and the Antarctic Peninsula.

The deglacial history of NW Alexander Island, Antarctica, from surface exposure dating

2012 ◽  
Vol 77 (2) ◽  
pp. 273-280 ◽  
Author(s):  
Joanne S. Johnson ◽  
Jeremy D. Everest ◽  
Philip T. Leat ◽  
Nicholas R. Golledge ◽  
Dylan H. Rood ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Antarctic Peninsula ◽  
Ice Sheet ◽  
Glacial Maximum ◽  
Ice Shelf ◽  
Last Glacial ◽  
Ice Cap ◽  
The Antarctic ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Recent changes along the margins of the Antarctic Peninsula, such as the collapse of the Wilkins Ice Shelf, have highlighted the effects of climatic warming on the Antarctic Peninsula Ice Sheet (APIS). However, such changes must be viewed in a long-term (millennial-scale) context if we are to understand their significance for future stability of the Antarctic ice sheets. To address this, we present nine new cosmogenic 10Be exposure ages from sites on NW Alexander Island and Rothschild Island (adjacent to the Wilkins Ice Shelf) that provide constraints on the timing of thinning of the Alexander Island ice cap since the last glacial maximum. All but one of the 10Be ages are in the range 10.2–21.7 ka, showing a general trend of progressive ice-sheet thinning since at least 22 ka until 10 ka. The data also provide a minimum estimate (490 m) for ice-cap thickness on NW Alexander Island at the last glacial maximum. Cosmogenic 3He ages from a rare occurrence of mantle xenoliths on Rothschild Island yield variable ages up to 46 ka, probably reflecting exhumation by periglacial processes.

Late Pleistocene colonization of South Georgia by yellow-billed pintails pre-dates the Last Glacial Maximum

2013 ◽  
Vol 40 (12) ◽  
pp. 2348-2360 ◽  
Author(s):  
Kevin G. McCracken ◽  
Robert E. Wilson ◽  
Jeffrey L. Peters ◽  
Kevin Winker ◽  
Anthony R. Martin
Keyword(s):  
Last Glacial Maximum ◽  
Late Pleistocene ◽  
Glacial Maximum ◽  
South Georgia ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Biodiversity signature of the Last Glacial Maximum at South Georgia, Southern Ocean

2016 ◽  
Vol 43 (12) ◽  
pp. 2391-2399 ◽  
Author(s):  
David K. A. Barnes ◽  
Chester J. Sands ◽  
Oliver T. Hogg ◽  
Ben J.O. Robinson ◽  
Rachel V. Downey ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
South Georgia ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

The onset of deglaciation of Cumberland Bay and Stromness Bay, South Georgia

2005 ◽  
Vol 17 (1) ◽  
pp. 29-32 ◽  
Author(s):  
N. VAN DER PUTTEN ◽  
C. VERBRUGGEN
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Aquatic Habitats ◽  
The Holocene ◽  
Carbon Dating ◽  
South Georgia ◽  
Last Glacial ◽  
Peat Deposits ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Carbon dating of basal peat deposits in Cumberland Bay and Stromness Bay and sediments from a lake in Stromness Bay, South Georgia indicates deglaciation at the very beginning of the Holocene before c. 9500 14C yr BP. This post-dates the deglaciation of one local lake which has been ice-free since at least 15 700 14C yr BP on account of its atypical geomorphological location. The latter indicates the likely presence of floristic refugia on South Georgia during the Last Glacial Maximum from which newly exposed terrestrial and aquatic habitats were rapidly colonized.

The relative influence of Laurentide and local ice sheets during the last glacial maximum in the eastern Chic-Chocs Range, northern Gaspé Peninsula, Quebec

2007 ◽  
Vol 44 (11) ◽  
pp. 1603-1625 ◽  
Author(s):  
Pawel Olejczyk ◽  
James T Gray
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Ice Caps ◽  
Ice Cap ◽  
The North ◽  
Gaspe Peninsula ◽  
The Last Glacial Maximum ◽  
Gaspé Peninsula ◽  
The Last Glacial

Geochemical signatures, erratic dispersal, and striae indicate glacial flows in the north-central Gaspé Peninsula exclusively from Appalachian sources, except for the coastal fringe. During the last glacial maximum (LGM), ice from the Monts McGerrigle flowed northward and northwestward over the summits of the eastern Chic-Chocs Range and the coastal plateau to the Gulf of St. Lawrence. Lesser flows also occurred to the north from Mont Albert and the western Chic-Chocs Range. Where intersecting striae were noted, the older flows are associated with a locally developed ice cap. The rare occurrences of striae and erratics, and morphometric and lithological characteristics of summit diamictons, imply limited basal erosion by both local and regional ice caps. This is postulated to result from early protection of rock surfaces by the initial buildup of thin, frozen-based ice in the eastern Chic-Chocs Range. A compact till mantle in the cols and on the coastal plateau and striae parallel to col directions indicate a downslope transition to wet-based ice. Occasional gneiss boulders above the marine limit between Cap-Chat and Sainte-Anne-des-Monts indicate a slight onlap of the Laurentide Ice Sheet (LIS), but the latter was excluded from the interior of the peninsula east of Cap-Chat. Whole-rock geochemistry from three granitoid erratics on Chic-Chocs summits and one in the York River basin indicates a local Devonian rather than a Precambrian Canadian Shield source. The absence of southward downwarping of synchronous postglacial marine limits across the Gaspé Peninsula corroborates this view for the LGM.

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