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Titel |
Area change of glaciers in the Canadian Rocky Mountains, 1919 to 2006 |
VerfasserIn |
C. Tennant, B. Menounos, R. Wheate, J. J. Clague |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1994-0416
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Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 6, no. 6 ; Nr. 6, no. 6 (2012-12-20), S.1541-1552 |
Datensatznummer |
250003883
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Publikation (Nr.) |
copernicus.org/tc-6-1541-2012.pdf |
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Zusammenfassung |
Glaciers in the Canadian Rocky Mountains constitute an important freshwater
resource. To enhance our understanding of the influence climate and local
topography have on glacier area, large numbers of glaciers of different sizes
and attributes need to be monitored over periods of many decades. We used
Interprovincial Boundary Commission Survey (IBCS) maps of the
Alberta–British Columbia (BC) border (1903–1924), BC Terrain Resource
Information Management (TRIM) data (1982–1987), and Landsat Thematic Mapper
(TM) and Enhanced Thematic Mapper (ETM+) imagery (2000–2002 and 2006) to
document planimetric changes in glacier cover in the central and southern
Canadian Rocky Mountains between 1919 and 2006. Over this period, glacier
cover in the study area decreased by 590 ± 70 km2 (40 ± 5%),
17 of 523 glaciers disappeared and 124 glaciers fragmented into multiple ice
masses. Glaciers smaller than 1.0 km2 experienced the greatest relative
area loss (64 ± 8%), and relative area loss is more variable with
small glaciers, suggesting that the local topographic setting controls the
response of these glaciers to climate change. Small glaciers with low slopes,
low mean/median elevations, south to west aspects, and high insolation
experienced the largest reduction in area. Similar rates of area change
characterize the periods 1919–1985 and 1985–2001;
−6.3 ± 0.6 km2 yr−1 (−0.4 ± 0.1% yr−1) and
−5.0 ± 0.5 km2 yr−1 (−0.5 ± 0.1% yr−1),
respectively. The rate of area loss, however, increased over the period
2001–2006; −19.3 ± 2.4 km2 yr−1
(−2.0 ± 0.2% yr−1). Applying size class-specific scaling
factors, we estimate a total reduction in glacier cover in the central and
southern Canadian Rocky Mountains for the period 1919–2006 of 750 km2
(30%). |
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