scholarly journals The last British Ice Sheet: growth, maximum extent and deglaciation

2002 ◽  
Vol 21 (2) ◽  
pp. 243-250 ◽  
Author(s):  
Lindsay J. Wilson ◽  
William E. N. Austin ◽  
Eystein Jansen
Keyword(s):  
1988 ◽  
Vol 25 (6) ◽  
pp. 938-941 ◽  
Author(s):  
John J. Clague ◽  
Ian R. Saunders ◽  
Michael C. Roberts

New radiocarbon dates on wood from two exposures in Chilliwack valley, southwestern British Columbia, indicate that this area was ice free and locally forested 16 000 radiocarbon years ago. This suggests that the Late Wisconsinan Cordilleran Ice Sheet reached its maximum extent in this region after 16 000 years BP. The Chilliwack valley dates are the youngest in British Columbia that bear on the growth of the Cordilleran Ice Sheet.


2012 ◽  
Vol 28 (1) ◽  
pp. 2-7 ◽  
Author(s):  
J. D. Everest ◽  
T. Bradwell ◽  
M. Stoker ◽  
S. Dewey

2015 ◽  
Vol 128 ◽  
pp. 48-68 ◽  
Author(s):  
Jared Lee Peters ◽  
Sara Benetti ◽  
Paul Dunlop ◽  
Colm Ó Cofaigh

Author(s):  
Joanna Ćwiąkała ◽  
Mateusz Moskalik ◽  
Jan Rodzik ◽  
Piotr Zagórski

AbstractThe glacial history of the Svalbard archipelago is often a hot topic for researches, but the articles usually refer to a particular piece of Svalbard. The authors of this work studied many scientific articles based on the researches to find and collect this history. Svalbard archipelago is located in the Arctic, at the edge of the continental shelf of Europe. The end of shelf boundary noted occurrence of ice caps in the past glaciations. In turn, the main elements of the landscape of the archipelago are glaciers that are currently in a recession. Spitsbergen (the biggest island of the archipelago) sets the limit of Pleistocene glaciations, and the current state of glaciers allows determining the place where the recession is intense. The main aim of the authors in this study is to show this history only from the late Vistulian to the late Holocene (the beginning of 21st century). Interstadials and Stadials start time varies, as their duration in different places, according to various authors. It is very hard to collect all information and describe this history. By knowing the history of glaciation, we can distinguish in the late Vistulian: Last Glacial Maximum (LGM), Bølling/Older Dryas/Allerød and Younger Dryas (YD). LGM was the stadial in which was the maximum extent of ice sheet in late Vistulian. After this period, ice sheet began to retreat from the continental shelf. In turn, YD was the stadial in which the last advance of glaciers took place, about 11 000 years BC. In the Holocene we can distinguish Holocene Climatic Optimum (in the meantime short Cooling Holocene), Revdalen Stadial, Medieval Warm Period, Little Ice Age (LIA) and 20th century warming. The maximum extent of glaciers in Holocene was in LIA. In LIA, the extent of glaciers was bigger than in YD. In 20th century a warming started and continues until now.


1976 ◽  
Vol 17 (75) ◽  
pp. 73-77
Author(s):  
C. M. Clapperton ◽  
D. E. Sugden

AbstractAlthough it is known that cirque glaciers once existed in the Falkland Islands, it has remained in doubt whether or not the islands were ever covered by ice caps or an ice sheet during the Cainozoic. This paper scrutinizes geomorphological evigernce on the south-eastern flank of a high massif in West Falkland. It is suggested that, at the time of their maximum extent in the Cainozoic, the largest glaciers were no more than 2.7 km long.


1977 ◽  
Vol 14 (11) ◽  
pp. 2614-2619 ◽  
Author(s):  
A. MacS. Stalker

The margin of a former Laurentide ice sheet is traced through southern and central Alberta, from the Saskatchewan border southeast of Medicine Hat to beyond Rocky Mountain House, southwest of Edmonton. This margin, which marks the limit of a significant glacier advance or readvance, is thought to represent the maximum extent of Laurentide ice on the Canadian prairies during Classical Wisconsin time. In the south this margin follows a well-developed hummocky moraine; in the north it is indicated mainly by a discordance in trend of ice-flow markings, a disruption of drainage, and a change in maturity of topography on either side.


1987 ◽  
Vol 119 (1) ◽  
pp. 49-53 ◽  
Author(s):  
Pjotr Oosterbroek ◽  
Ida R.M. Tangelder

AbstractSubspeciation in the circumpolar Nephrotoma lundbecki is discussed for a population from south of the Laurentide Ice Sheet, described here as N.l. alexanderi. For 18 nearctic Nephrotoma species new distribution records are presented, mainly from the northern Nearctic, adding considerably to our knowledge of the distribution of these species. Included is the second nearctic record of the palaearctic species Nephrotoma cornicina (L.).


2020 ◽  
Author(s):  
Nicolás E. Young ◽  
Alia J. Lesnek ◽  
Josh K. Cuzzone ◽  
Jason P. Briner ◽  
Jessica A. Badgeley ◽  
...  

Abstract. During the middle to late Holocene (8.2 ka BP to present), the Greenland Ice Sheet (GrIS) was smaller than its current configuration. Determining the exact dimensions of the Holocene ice-sheet minimum and the duration that the ice margin rested inboard of its current position remains challenging. Contemporary retreat of the GrIS from its historical maximum extent in southwestern Greenland is exposing a landscape that holds clues regarding the configuration and timing of past ice-sheet minima. To quantify the duration of the time the GrIS margin was near its modern extent we develop a new technique on Greenland that utilizes in situ cosmogenic 10Be-14C-26Al in bedrock samples that have become ice free only in the last few decades by the retreating ice-sheet margin at Kangiata Nunaata Sermia (n = 12 sites; KNS), southwest Greenland. To maximize the utility of this approach, we refine the deglaciation history of the region with stand-alone 10Be measurements (n = 49) and traditional 14C ages from sedimentary deposits contained in proglacial-threshold lakes. We combine our reconstructed ice-margin history in the KNS region with additional geologic records from southwestern Greenland and recent model simulations of GrIS change, to constrain the timing of the GrIS minimum in southwest Greenland, the magnitude of Holocene inland GrIS retreat, and explore the regional climate history influencing Holocene ice-sheet behavior. Our 10Be-14C-26Al measurements reveal that 1) KNS retreated behind its modern margin just before 10 ka, but likely stabilized near the present GrIS margin for several thousand years before retreating farther inland, and 2) pre-Holocene 10Be detected in several of our sample sites is most easily explained by several thousand years of surface exposure during the Last Interglaciation. Moreover, our new results indicate that the minimum extent of the GrIS likely occurred after ~ 5 ka, and the GrIS margin may have approached its eventual historical maximum extent as early as ~ 2 ka. Recent simulations of GrIS change are able to match the geologic record of ice-sheet change in regions dominated by surface mass balance, but produce a poorer model-data fit in areas influenced by oceanic and dynamic processes. Simulations that achieve the best model-data fit suggest that inland retreat of the ice margin driven by early to middle Holocene warmth may have been mitigated by increased precipitation. Triple 10Be-14C-26Al measurements in recently deglaciated bedrock provide a new tool to help decipher the duration of smaller-than-present ice over multiple timescales. Modern retreat of the GrIS margin in southwest Greenland is revealing a bedrock landscape that was also exposed during the migration of the GrIS margin towards its Holocene minimum extent, but has yet to tap into a landscape that remained ice covered throughout the entire Holocene.


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