Pattern and chronology of glacial Lake Peace shorelines and implications for isostacy and ice-sheet configuration in northeastern British Columbia, Canada

Boreas ◽  
2015 ◽  
Vol 44 (2) ◽  
pp. 288-304 ◽  
Author(s):  
Adrian S. Hickin ◽  
Olav B. Lian ◽  
Victor M. Levson ◽  
Yao Cui
Keyword(s):  
British Columbia ◽  
Ice Sheet ◽  
Glacial Lake

scholarly journals The pattern and style of deglaciation at the Late Wisconsinan Laurentide and Cordilleran ice sheet limits in northeastern British Columbia

2017 ◽  
Vol 54 (1) ◽  
pp. 52-75 ◽  
Author(s):  
David H. Huntley ◽  
Adrian S. Hickin ◽  
Olav B. Lian
Keyword(s):  
British Columbia ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Yukon Territory ◽  
Glacial Lake ◽  
Glacial Lakes ◽  
Lake Formation ◽  
Late Wisconsinan ◽  
Cordilleran Ice Sheet ◽  
Lake Deposits

This paper reports on the landform assemblages at the northern confluence of the Late Wisconsinan Laurentide and Cordilleran ice sheets with montane and piedmont glaciers in the northern Rockies and southern Mackenzie Mountains. Recent observations in northeastern British Columbia refine our knowledge of the pattern and style of ice sheet retreat, glacial lake formation, and meltwater drainage. At the onset of deglaciation, confluent Laurentide and Cordilleran terminal ice margins lay between 59°N, 124°30′W and 60°N, 125°15′W. From this terminal limit, ice sheets retreated into north-central British Columbia and Yukon Territory, with remnant Cordilleran ice and montane glaciers confined to mountain valleys and the Liard Plateau. Distinctive end moraines are not associated with the retreat of Cordilleran ice in these areas. Laurentide ice retreated northeastward from uplands and the plateaus; then separated into lobes occupying the Fort Nelson and Petitot river valleys. Ice-retreat landforms include recessional end moraines (sometimes overridden and drumlinized), hill–hole pairs, crevasse-fill deposits, De Geer-like ribbed till ridges, hummocky moraines, kames, meltwater features, and glacial lake deposits that fall within the elevation range of glacial Lake Liard and glacial Lake Fort Nelson (ca. 840–380 m). Meltwater and sediment transport into glacial lakes Fort Nelson, Liard, Nahanni, and Mackenzie was sustained by remnant ice in the Liard River and Fort Nelson River drainage basins until the end of glaciation. Optical dating of sand from stabilized parabolic dunes on the Liard Plateau indicates that proglacial conditions, lake formation, and drainage began before 13.0 ± 0.5 ka (calendar years). The Petitot, Fort Nelson, and Liard rivers all occupy spillways incised into glacial deposits and bedrock by meltwater overflow from glacial lakes Peace and Hay.

Late-glacial lakes in the Thompson Basin, British Columbia: paleogeography and evolution

2004 ◽  
Vol 41 (11) ◽  
pp. 1367-1383 ◽  
Author(s):  
Timothy F Johnsen ◽  
Tracy A Brennand
Keyword(s):  
British Columbia ◽  
New Technologies ◽  
Ice Sheet ◽  
River System ◽  
Late Glacial ◽  
Dam Failure ◽  
Glacial Lake ◽  
Lake Basin ◽  
Glacial Lakes ◽  
Positioning Systems

During the decay of the Cordilleran Ice Sheet 10 000 – 13 000 BP, glacial lakes developed within valleys that dissect the Interior Plateau of British Columbia. In this paper, we (1) illustrate a procedure for assessing paleo water planes that has general application, (2) document lake paleogeography and evolution in the Thompson Valley, (3) provide new data on the glacio-isostatic response of the central Cordillera, and (4) present new evidence of its late-glacial environment. We employ geomorphology and sedimentology, digital elevation models, and new technologies (differential global positioning systems, ground penetrating radar, and geographic information systems) to refine paleogeographic reconstructions of glacial lakes. Glacial Lake Thompson and Glacial Lake Deadman were ribbon-shaped (width to length ratio ≈ 3:100), deep (>>140 to ~50 m) lakes that contained significant water volumes (84–24 km3). They lengthened to the west and their water level lowered as ice decayed. Final ice dam failure resulted in an ~20 km3 jökulhlaup that eroded bedforms and deposited flood eddy bars within the lake basin, travelled ~250 km along the Fraser River system, and may have deposited exotic mud offshore between 10 190 and 11 940 BP. Glacio-isostatic tilts of water planes are among the highest in the world (1.7–1.8 m km–1). Their orientations suggest that ice sheet loads were greater or longer- lived to the north-northwest of the study area, lending support to the notion of an ice divide centred on the Fraser Plateau.

Ice-free conditions in southwestern British Columbia at 16000 years BP

1988 ◽  
Vol 25 (6) ◽  
pp. 938-941 ◽  
Author(s):  
John J. Clague ◽  
Ian R. Saunders ◽  
Michael C. Roberts
Keyword(s):  
British Columbia ◽  
Ice Sheet ◽  
Radiocarbon Dates ◽  
Maximum Extent ◽  
Late Wisconsinan ◽  
Cordilleran Ice Sheet

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.

Periodic JöKulhlaups from Pleistocene Glacial Lake Missoula—New Evidence from Varved Sediment in Northern Idaho and Washington

1984 ◽  
Vol 22 (1) ◽  
pp. 46-58 ◽  
Author(s):  
Richard B. Waitt
Keyword(s):  
Ice Sheet ◽  
Glacial Lake ◽  
Gravel Beds ◽  
Varved Sediment ◽  
Cordilleran Ice Sheet ◽  
Northern Idaho ◽  
New Evidence ◽  
Stratigraphic Succession ◽  
Conventional Idea ◽  
Sand Beds

Newly examined exposures in northern Idaho and Washington show that catastrophic floods from glacial Lake Missoula during late Wisconsin time were repeated, brief jökulhlaups separated by decades of quiet glaciolacustrine and subaerial conditions. Glacial Priest Lake, dammed in the Priest River valley by a tongue of the Purcell trench lobe of the Cordilleran ice sheet, generally accumulated varved mud; the varved mud is sharply interrupted by 14 sand beds deposited by upvalley-running currents. The sand beds are texturally and structurally similar to slackwater sediment in valleys in southern Washington that were backflooded by outbursts from glacial Lake Missoula. Beds of varved mud also accumulated in glacial Lake Spokane (or Columbia?) in Latah Creek valley and elsewhere in northeastern Washington; the mud beds were disrupted, in places violently, during emplacement of each of 16 or more thick flood-gravel beds. This history corroborates evidence from southern Washington that only one graded bed is deposited per flood, refuting a conventional idea that many beds accumulated per flood. The total number of such floodlaid beds in stratigraphic succession near Spokane is at least 28. The mud beds between most of the floodlaid beds in these valleys each consist of between 20 and 55 silt-to-clay varves. Lacustrine environments in northern Idaho and Washington therefore persisted for two to six decades between regularly recurring, colossal floods from glacial Lake Missoula.

scholarly journals Englacial lake dynamics within a Pleistocene cordilleran ice sheet at Kima' Kho tuya (British Columbia, Canada)

2021 ◽  
Vol 273 ◽  
pp. 107247
Author(s):  
James K. Russell ◽  
Benjamin R. Edwards ◽  
Marie Turnbull ◽  
Lucy A. Porritt
Keyword(s):  
British Columbia ◽  
Ice Sheet ◽  
Cordilleran Ice Sheet ◽  
Lake Dynamics

scholarly journals Historie retreat of Grand Pacific and Melbern Glaciers, Saint Elias Mountains, Canada: an analogue for decay of the Cordilleran ice sheet at the end of the Pleistocene?

1994 ◽  
Vol 40 (134) ◽  
pp. 205-210
Author(s):  
John J. Clague ◽  
S. G. Evans
Keyword(s):  
British Columbia ◽  
Ice Sheet ◽  
Marginal Land ◽  
Terminal Pleistocene ◽  
Cordilleran Ice Sheet

AbstractGrand Pacific and Melbern Glaciers, two of the largest valley glaciers in British Columbia, have decreased over 50% in volume in the last few hundred years (total ice loss = 250–300km3). Melbern Glacier has thinned 300–600 m and retreated 15 km during this period; about 7 km of this retreat occurred between the mid-1970s and 1987, accompanied by the formation of one of the largest presently existing, ice-dammed lakes on Earth. Grand Pacific Glacier, which terminates in Tarr Inlet at the British Columbia–Alaska boundary, retreated 24 km between 1879 and 1912. This rapid deglaciation has destabilized adjacent mountain slopes and produced spectacular ice-marginal land forms. The sediments and land forms produced by historic deglaciation in Melbern-Grand Pacific valley are comparable, both in style and scale, to those associated with the decay of the Cordilleran ice sheet at the end of the Pleistocene (c. 14–10 ka BP). Rates of historic and terminal Pleistocene deglaciation also may be comparable.

Catastrophic glacial-lake outburst flooding of the Patagonian Ice Sheet

2020 ◽  
Vol 200 ◽  
pp. 102996 ◽  
Author(s):  
Gerardo Benito ◽  
Varyl R. Thorndycraft
Keyword(s):  
Ice Sheet ◽  
Glacial Lake
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