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TitleChanges in late-Neoglacial perennial snow/ice extent and equilibrium-line altitudes in the Queen Elizabeth Islands, Arctic Canada
AuthorWolken, G J; England, J H; Dyke, A S
SourceThe Holocene vol. 18, no. 4, 2008 p. 615-627,
Alt SeriesEarth Sciences Sector, Contribution Series 20080187
Alt SeriesPolar Continental Shelf Project, Contribution 003-07
PublisherSAGE Publications
Mediapaper; on-line; digital
File formatpdf (Adobe® Reader®)
NTS29G; 38F; 38G; 39; 48E; 48F; 48G; 48H; 49; 58E; 58F; 58G; 58H; 59; 68E; 68F; 68G; 68H; 69; 78E; 78F; 78G; 78H; 79; 88E; 88F; 88G; 88H; 89; 98E; 98H; 99A; 99D; 120; 340; 560
AreaCanadian Arctic; Canadian Arctic Archipelago; Queen Elizabeth Islands
Lat/Long WENS-124.0000 -60.0000 84.0000 74.0000
Subjectssurficial geology/geomorphology; Nature and Environment; Recent; paleoenvironment; paleoclimatology; glaciation; neoglaciation; ice sheets; vegetation; trimlines; snow; ice margins; ice retreat; glaciers; climate; satellite imagery; infrared spectral analyses; satellites; LANDSAT; Little Ice Age; climate change; plateau ice caps; seasonal snow cover; climate indicators; equilibrium-line altitude (ELA); multispectral analyses; snow extent; LANDSAT thematic mapper imagery; LANDSAT 7; Enhanced Thematic Mapper Plus (ETM+); Terra satellite; Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER); Phanerozoic; Cenozoic; Quaternary
Illustrationssketch maps; satellite images; aerial photographs; tables; graphs
ProgramEnhancing resilience in a changing climate
ProgramNSERC Natural Sciences and Engineering Research Council of Canada
ProgramUniversity of Alberta, Canadian Circumpolar Institute, Northern Research Grants
ProgramPolar Continental Shelf Program
Released2008 06 01
AbstractChanges in late Neoglaical climate resulted in extensive modification of Arctic terrestrial ice cover. A substantial reduction in terrestrial ice cover in the Queen Elizabeth Islands (QEI) following the 'Little Ice Age' (LIA) (~AD 1250-1900), is indicated by widespread, light-toned patches of poorly vegetated terrain, extending back to the modern ice mass. These patches display abrupt outer margins (trimlines), which record the former position and maximum extent of perennial snow/ice and, in many cases, mark the former equilibrium-line altitude (ELA). Trimlines surrounding terrain formerly covered by LIA perennial snow/ice were mapped using multispectral classification approaches applied to high-resolution satellite imagery. ELAs were reconstructed from trimlines associated with former perennial snow/ice produced by long-term snowline lowering. Between the end of the LIA and 1960, the area of terrestrial ice in the QEI decreased by 37% (62 387 km2). Most of this reduction (94%) occurred in the eastern QEI where the majority of the ice exists today; however, a 100% reduction in ice cover occurred on many of the western islands by 1960, an effect largely controlled by the subtle topography of these islands. The reconstructed LIA ELA trend surface was used with the 1960 mapped ELAs to calculate spatial variations in the change in height (delta h) of the ELA trend surface throughout the QEI during the first half of the twentieth century. ELA delta h between the LIA and 1960 reveal a high degree of local variability in the mountainous regions, ranging from 0 to >600 m; however a strong regional-scale pattern of change is shown over the QEI as a whole.