DOI: 10.5194/tc-15-2021-2021
论文题名: Evolution of the firn pack of Kaskawulsh Glacier, Yukon: Meltwater effects, densification, and the development of a perennial firn aquifer
作者: Ochwat N.E. ; Marshall S.J. ; Moorman B.J. ; Criscitiello A.S. ; Copland L.
刊名: Cryosphere
ISSN: 19940416
出版年: 2021
卷: 15, 期: 4 起始页码: 2021
结束页码: 2040
语种: 英语
英文关键词: ablation
; aquifer
; drawdown
; energy balance
; firn
; geodetic network
; meltwater
; surface energy
; Alaska
; Canada
; Kaskawulsh Glacier
; Saint Elias Mountains
; St Elias Mountains
; United States
; Yukon Territory
英文摘要: In spring 2018, two firn cores (21 and 36 m in length) were extracted from the accumulation zone of Kaskawulsh Glacier, St. Elias Mountains, Yukon. The cores were analyzed for ice layer stratigraphy and density and compared against historical measurements made in 1964 and 2006. Deep meltwater percolation and refreezing events were evident in the cores, with a total ice content of >2.33±0.26< m in the 36 m core and liquid water discovered below a depth of 34.5 m. Together with the observed ice content, surface energy balance and firn modelling indicate that Kaskawulsh Glacier firn retained about 86 % of its meltwater in the years 2005-2017. For an average surface ablation of 0.38 m w.e. yr>-1< over this period, an estimated 0.28 m w.e. yr>-1< refroze in the firn, 0.05 m w.e. yr>-1< was retained as liquid water, and 0.05 m w.e. yr>-1< drained or ran off. The refrozen meltwater is associated with a surface lowering of >0.73±0.23< m between 2005 and 2017 (i.e., surface drawdown that has no associated mass loss). The firn has become denser and more ice-rich since the 1960s and contains a perennial firn aquifer (PFA), which may have developed over the past decade. This illustrates how firn may be evolving in response to climate change in the St. Elias Mountains, provides firn density information required for geodetic mass balance calculations, and is the first documented PFA in the Yukon-Alaska region. © 2021 BMJ Publishing Group. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164774
Appears in Collections: 气候变化与战略
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作者单位: Department of Geography, University of Calgary, Calgary, Alberta T2N 1N4, Canada; Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, 80309, United States; Environment and Climate Change Canada, Gatineau, Quebec K1A 0H3, Canada; Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, T6G 2R3, Canada; Department of Geography, Environment and Geomatics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
Recommended Citation:
Ochwat N.E.,Marshall S.J.,Moorman B.J.,et al. Evolution of the firn pack of Kaskawulsh Glacier, Yukon: Meltwater effects, densification, and the development of a perennial firn aquifer[J]. Cryosphere,2021-01-01,15(4)