气候变化领域集成服务门户(CCPortal): The Holocene history of the Columbia Icefield; Canada

CCPortal

DOI	10.1016/j.quascirev.2020.106436
	The Holocene history of the Columbia Icefield; Canada
	Luckman B.H.; Sperling B.J.R.; Osborn G.D.
发表日期	2020
ISSN	0277-3791
卷号	242
英文摘要	The Columbia Icefield is the largest icefield in the Canadian Rockies and feeds eight major glaciers that drain to three different oceans. Previous glacier studies have focused on Athabasca and Saskatchewan Glaciers, primarily due to their easy access. This paper reviews evidence of the Holocene history from all eight glaciers. Maximum Holocene glacier extent was during the Little Ice Age (LIA) with dating based mainly on minimum tree-ring estimates from trees growing on the moraines or from trees scarred, tilted or killed by the glaciers. The LIA maximum advance was during the 19th century at Athabasca (1843/4), Dome (1846), Saskatchewan (1862) and Castleguard (<1858) Glaciers but during the 18th century at Manitoba (1740), Columbia (<1739), Kitchener (<1713) and Stutfield (1758). Advances in 1714 (Athabasca) and 1733 (Saskatchewan) were of almost equal extent to the 19th century maxima. Early LIA advances are identified from a buried in-situ stump at Stutfield (>1271) and detrital wood from lateral moraines at Columbia (ca. 0.8-0.7ka). Two overridden stumps at Columbia Glacier indicate a previously unidentified advance ca 1500 A.D. These four phases of LIA coincide with major reductions in summer temperatures reconstructed at the Icefield. There are also undated (pre-1600, possibly pre LIA) moraines at Kitchener Glacier. Less extensive Neoglacial glacier events are documented by an in-situ forest bed buried by the Saskatchewan Glacier (ca 2.90–3.4 ka., equivalent to the “Peyto advance”) and stumps buried by till ca. 4.2ka at Boundary Glacier. Detrital wood recovered from till at Columbia Glacier indicates at least one glacier advance ca 2.0-2.2ka. Till exposed between the Bridge River and Mazama tephras at Stutfield Glacier includes detrital wood dating 2.22–2.70 ka that possibly indicates a glacier advance immediately prior to the Bridge River tephra. Regional paleoenvironmental data indicate warmer conditions and higher treelines in the early Holocene. Detrital wood washed out of Dome and Athabasca Glaciers indicates trees were present in these valleys ca 6, 7 and 9ka upvalley of present glacier snouts. Evidence from Castleguard cave indicates upstream entrances below the present Icefield were probably ice free ca 9.5ka indicating the icefield was much reduced in extent at that time. The detrital wood may represent wood killed and reworked by limited glacier advances from the Icefield, far upstream of present glacier fronts, at these times. © 2020 Elsevier Ltd
英文关键词	Columbia Icefield; Dendroglaciology; Glacier fluctuations; Holocene; Little Ice Age; Neoglacial
语种	英语
scopus关键词	Domes; Forestry; 18th century; 19th century; Early Holocene; Little Ice Age; Saskatchewan; Summer temperature; Tree rings; Warmer conditions; Wood; glacier advance; Holocene; ice field; Little Ice Age; moraine; Neoglacial; nineteenth century; reconstruction; tree ring; Alaska; Alberta; Athabasca Glacier; Bridge River; British Columbia; Canada; Columbia Glacier; Kitchener; Manitoba; Ontario [Canada]; Saskatchewan; United States; Mazama
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151386
作者单位	Department of Geography, University of Western Ontario, London, ON N6A 5C2, Canada; Department of Geoscience, University of Calgary, Calgary, AB T2N 1N4, Canada
推荐引用方式 GB/T 7714	Luckman B.H.,Sperling B.J.R.,Osborn G.D.. The Holocene history of the Columbia Icefield; Canada[J],2020,242.
APA	Luckman B.H.,Sperling B.J.R.,&Osborn G.D..(2020).The Holocene history of the Columbia Icefield; Canada.Quaternary Science Reviews,242.
MLA	Luckman B.H.,et al."The Holocene history of the Columbia Icefield; Canada".Quaternary Science Reviews 242(2020).