دورية أكاديمية
Oscillatory subglacial drainage in the absence of surface melt
| العنوان: | Oscillatory subglacial drainage in the absence of surface melt |
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| المؤلفون: | C. Schoof, C. A Rada, N. J. Wilson, G. E. Flowers, M. Haseloff |
| المصدر: | The Cryosphere, Vol 8, Iss 3, Pp 959-976 (2014) |
| بيانات النشر: | Copernicus Publications, 2014. |
| سنة النشر: | 2014 |
| المجموعة: | LCC:Environmental sciences LCC:Geology |
| مصطلحات موضوعية: | Environmental sciences, GE1-350, Geology, QE1-996.5 |
| الوصف: | 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. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 1994-0416 1994-0424 |
| Relation: | http://www.the-cryosphere.net/8/959/2014/tc-8-959-2014.pdf; https://doaj.org/toc/1994-0416; https://doaj.org/toc/1994-0424 |
| DOI: | 10.5194/tc-8-959-2014 |
| URL الوصول: | https://doaj.org/article/858b8c93176745758636220d4d23011c |
| رقم الأكسشن: | edsdoj.858b8c93176745758636220d4d23011c |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 19940416 19940424 |
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| DOI: | 10.5194/tc-8-959-2014 |