DOI: 10.5194/tc-10-87-2016
Scopus记录号: 2-s2.0-85009423395
论文题名: Ablation from calving and surface melt at lake-terminating Bridge Glacier, British Columbia, 1984-2013
作者: Chernos M ; , Koppes M ; , Moore R ; D
刊名: Cryosphere
ISSN: 19940416
出版年: 2016
卷: 10, 期: 1 起始页码: 87
结束页码: 102
语种: 英语
英文关键词: ablation
; energy balance
; equilibrium line
; glacier mass balance
; glacier retreat
; iceberg calving
; melt
; regional climate
; spatiotemporal analysis
; valley glacier
; Bridge River
; British Columbia
; Canada
; Coast Mountains
英文摘要: Bridge Glacier is a lake-calving glacier in the Coast Mountains of British Columbia and has retreated over 3.55 km since 1972. The majority of this retreat has occurred since 1991. This retreat is substantially greater than what has been inferred from regional climate indices, suggesting that it has been driven primarily by calving as the glacier retreated across an overdeepened basin. In order to better understand the primary drivers of ablation, surface melt (below the equilibrium line altitude, ELA) and calving were quantified during the 2013 melt season using a distributed energy balance model (DEBM) and time-lapse imagery. Calving, estimated using areal change, velocity measurements, and assuming flotation were responsible for 23 % of the glacier's ablation below the ELA during the 2013 melt season and were limited by modest flow speeds and a small terminus cross-section. Calving and surface melt estimates from 1984 to 2013 suggest that calving was consistently a smaller contributor of ablation. Although calving was estimated to be responsible for up to 49 % of the glacier's ablation for individual seasons, averaged over multiple summers it accounted between 10 and 25 %. Calving was enhanced primarily by buoyancy and water depths, and fluxes were greatest between 2005 and 2010 as the glacier retreated over the deepest part of Bridge Lake. The recent rapid rate of calving is part of a transient stage in the glacier's retreat and is expected to diminish within 10 years as the terminus recedes into shallower water at the proximal end of the lake. These findings are in line with observations from other lake-calving glacier studies across the globe and suggest a common large-scale pattern in calving-induced retreat in lake-terminating alpine glaciers. Despite enhancing glacial retreat, calving remains a relatively small component of ablation and is expected to decrease in importance in the future. Hence, surface melt remains the primary driver of ablation at Bridge Glacier and thus projections of future retreat should be more closely tied to climate. © 2016 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75200
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Department of Geography, University of British Columbia, 1984 West Mall, Vancouver, BC, Canada; Department of Forest Resources Management, Forest Sciences Centre, 2424 Main Mall, Vancouver, BC, Canada
Recommended Citation:
Chernos M,, Koppes M,, Moore R,et al. Ablation from calving and surface melt at lake-terminating Bridge Glacier, British Columbia, 1984-2013[J]. Cryosphere,2016-01-01,10(1)