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TitreSpatial patterns of snow accumulation across Belcher Glacier, Devon Ice Cap, Nunavut, Canada
AuteurSylvestre, T; Copland, L; Demuth, M N; Sharp, M
SourceJournal of Glaciology vol. 59, no. 217, 2013 p. 874-882, https://doi.org/10.3189/2013JoG12J227
Année2013
Séries alt.Secteur des sciences de la Terre, Contribution externe 20110344
ÉditeurJournal of Glaciology
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.3189/2013JoG12J227
Mediapapier; en ligne; numérique
Formatspdf
ProvinceNunavut
SNRC48H/10; 48H/11; 48H/14; 48H/15
Lat/Long OENS -83.0000 -81.0000 76.0000 75.5000
Sujetssondes radar; géoradar; imagerie radar; glaciers; diagraphie de sondages neutronique; neige; glace; concentration de glace; géologie de l'environnement
Illustrationslocation maps; tables; core logs; satellite images
ProgrammeLes sciences de la Terre à l'appui de la caractérisation, à l'échelle nationale, des impacts des changements climatiques sur la masse continentale canadienne, Géosciences de changements climatiques
Résumé(disponible en anglais seulement)
Ground-penetrating radar (GPR) surveys at a center frequency of 500MHz were used to determine winter (2007/08) and net annual (2005-07) snow water equivalent (SWE) patterns across the upper parts of Belcher Glacier, Devon Ice Cap, Nunavut, Canada. The GPR measurements were validated against snow depths determined from avalanche probe measurements, and converted to SWE values using densities measured with a down-borehole neutron density probe and in shallow snow pits. Distinct internal reflection horizons (IRHs) in the GPR record were formed during warm summers in 2007 and 2005, and a large rain event in summer 2006 which caused ice to accumulate above the 2005 melt surface. Elevation provides the dominant control on winter SWE distribution across the basin, with surface topography (e.g. gullies) also being locally important. Based on the location where IRHs intersected the ice-cap surface, the basin-wide firn line occurred at an altitude of 1260-1300m over the period 2005-08. Net mass balance across the accumulation area of Belcher Glacier averaged 0.24mw.e. a-1 over the period 2005-07, mainly dependent on altitude. This is a little higher than most previous estimates for the period since the 1960s, although the differences lie within error limits.
GEOSCAN ID289842