气候变化领域集成服务门户(CCPortal): Oscillatory subglacial drainage in the absence of surface melt

CCPortal

DOI	10.5194/tc-8-959-2014
	Oscillatory subglacial drainage in the absence of surface melt
	Schoof C.; Rada C.A.; Wilson N.J.; Flowers G.E.; Haseloff M.
发表日期	2014
ISSN	19940416
卷号	8 期号:3
英文摘要	The presence of strong diurnal cycling in basal water pressure records obtained during the melt season is well established for many glaciers. The behaviour of the drainage system outside the melt season is less well understood. Here we present borehole observations from a surge-type valley glacier in the St Elias Mountains, Yukon Territory, Canada. Our data indicate the onset of strongly correlated multi-day oscillations in water pressure in multiple boreholes straddling a main drainage axis, starting several weeks after the disappearance of a dominant diurnal mode in August 2011 and persisting until at least January 2012, when multiple data loggers suffered power failure. Jökulhlaups provide a template for understanding spontaneous water pressure oscillations not driven by external supply variability. Using a subglacial drainage model, we show that water pressure oscillations can also be driven on a much smaller scale by the interaction between conduit growth and distributed water storage in smaller water pockets, basal crevasses and moulins, and that oscillations can be triggered when water supply drops below a critical value. We suggest this in combination with a steady background supply of water from ground water or englacial drainage as a possible explanation for the observed wintertime pressure oscillations. © Author(s) 2014.
学科领域	data set; diurnal variation; glacial environment; growth; melting; pressure effect; subglacial environment; water supply; Saint Elias Mountains
语种	英语
scopus关键词	data set; diurnal variation; glacial environment; growth; melting; pressure effect; subglacial environment; water supply; Saint Elias Mountains
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/120107
作者单位	Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada; Department of Earth Sciences, Simon Fraser University, Burnaby, BC, Canada
推荐引用方式 GB/T 7714	Schoof C.,Rada C.A.,Wilson N.J.,et al. Oscillatory subglacial drainage in the absence of surface melt[J],2014,8(3).
APA	Schoof C.,Rada C.A.,Wilson N.J.,Flowers G.E.,&Haseloff M..(2014).Oscillatory subglacial drainage in the absence of surface melt.Cryosphere,8(3).
MLA	Schoof C.,et al."Oscillatory subglacial drainage in the absence of surface melt".Cryosphere 8.3(2014).