Browsing by Author "Osborn, Gerald D."
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Item Embargo Changes in Calgary's groundwater levels and some related environmental consequences : a four-dimen(1990) Rajewicz, Rene; Osborn, Gerald D.Item Open Access Changes in Calgary's groundwater levels and some related environmental consequences: a four-dimensional model(1990) Rajewicz, Rene; Osborn, Gerald D.Item Open Access Evidence of latest pleistocene glacier advance in the southern Coast Mountains, Britsh Columbia, Canada(2006) Minkus, Ryan Scott; Osborn, Gerald D.Item Open Access Fluvial geomorphology, sedimentology and paleohydrology of the piedmont east of Glacier National Park, Montana(1988) du Toit, Charl; Osborn, Gerald D.Item Open Access Holocene and latest Pleistocene paleoenvironments of the Mission Mountains, northwestern Montana(1994) Gerloff, Lisa M.; Osborn, Gerald D.Item Open Access Holocene glacier fluctuations on Mount Baker, Washington, USA(2009) Ryane, Chanone; Osborn, Gerald D.; Menounos, BrianItem Embargo Late Pleistocene and Holocene cirque glaciations in the Shuswap Highland area, British Columbia(1976) Duford, James Matthew; Osborn, Gerald D.Item Open Access Late quaternary geology of the Upper Elk Valley, British Columbia(1978) Ferguson, Angus J.; Osborn, Gerald D.Item Open Access Late quaternary paleoenvironmental reconstruction of the Beauvais Lake area, Alberta(1994) Powers, Jeffrey Steven; Osborn, Gerald D.Item Open Access Latest Pleistocene and Holocene glacier fluctuations in Mount Rainier National Park, Washington, USA(2011) Samolczyk, Mary; Osborn, Gerald D.Item Open Access Latest pleistocene and holocene paleo-environments, Rose Basin, Glacier National Park, MT(2003) MacLeod, David Matthew; Osborn, Gerald D.Item Open Access Quaternary environmental change in the Stikine Plateau region, northwestern British Columbia, Canada(1994) Spooner, Ian Stewart; Osborn, Gerald D.Records of Quaternary environmental change have been resolved on the Stikine Plateau of northwestern British Columbia. Glacial sediment has been preserved between Early Pleistocene basalt flows on Mt. Edziza and underneath Middle Pleistocene basalt flows in the Stikine River valley. The Mt. Edziza record indicates that regional ice advanced from the southwest and west of Mt. Edziza and inundated the plateau. Radiometric and paleomagnetic dating indicates sediment deposition occurred during isotope stages 24 to 26. Paleomagnetic sampling resulted in the resolution of the Jaramillo normal polarity event within the section. The Stikine River valley section indicates that river blockage and glaciolacustrine sediment deposition occurred at about 330 ± 30 ka (isotope stage 10). The blockage was a result of early ice advance in the Coast Mountains and eventual regional ice cover is indicated by till overlying the glaciolacustrine sediment. Advance-phase glaciolacustrine sediment deposited in the Stikine River valley is a record of blockage of the Stikine River by alpine glaciation during early Fraser glaciation time. The extent and thickness (>150 m) of the section indicates that a considerable lag occurred between alpine and Cordilleran ice advance into the region. Boulder lags, perched meltwater paleochannels and extensive scouring indicate that post-glacial fluvial incision was swift and that stagnant ice may have resided in the valley during deglaciation. A palynological investigation of Susie Lake, eastern Boundary Ranges, Coast Mountains, has yielded a comprehensive Late Quaternary biostratigraphic record. Paleovegetational zones record initial colonization (by 10,000 - 7800 BP), establishment of a spruce and fir forest ecotone established by warming climate (about 7800-4200 BP), gradual cooling and precipitation inc·rease accompanied by migration of lodgepole pine into the region (about 4200 - 2100 BP) and moist and cool conditions and a lowering of treeline (about 2100 BP - Present). Late Holocene oral history records are powerful tools for the resolution of physical environmental change in remote, isolated areas. Landslides have produced river blockage and flooding; the landslides occur in unstable lacustrine deposits and failure is triggered by concentrated spring runoff. Volcanic activity may have occurred as little as 160 years ago. Although subsequent verification is desirable, oral histories may provide the initial evidence of past geological events.Item Open Access Quaternary geology of Hoodoo Mountain Volcano, northwestern British Columbia(2006) MacDonald, Fiona H.; Osborn, Gerald D.Item Open Access Structural deformation along the Red Deer River Valley, Drumheller, Alberta(2005) Hodgins, Dawn C.; Spratt, Deborah A.; Osborn, Gerald D.Item Open Access Using Flowband Modelling to Reconstruct Volume Change of Athabasca Glacier in the Canadian Rocky Mountains over the Last Millennium(2018-05-22) Nath, Rituparna; Marshall, Shawn; Osborn, Gerald D.; Yackel, John J.Glaciers respond strongly to small climatic shifts, so records of historical glacier change can be used to reconstruct past climate. In turn, understanding glacier sensitivity to climate variability is important for regional water resource management and for projecting glacier response to ongoing climate change. We develop an enhanced flow-band model of glacier dynamics to simulate the past and future extent of glaciers in the Canadian Rocky Mountains, with the aim of coupling this model within larger scale regional climate models of glacier response to climate change. Longitudinal stress and valley shape factors are introduced to provide a more complete treatment of glacier dynamics. This presentation focuses on glacier volume reconstructions over the last millennium for Athabasca Glacier, Alberta, Canada, with a particular focus on glacier reconstructions in the Little Ice Age (LIA). Athabasca Glacier, located on the continental divide of the Canadian Rocky Mountains, is the second largest outlet of the Columbia Icefield. With the availability of SPOT 5 imagery, digital elevation models, and the ArcGIS Hydro tool, ice catchment properties, glacier width, and LIA moraines have been extracted using automated procedures. I model glacier thickness, volume, and mass change for different climate and glaciological parametrizations that give good reconstructions of LIA ice extent. Dated lateral and terminal moraines provide geological control on the LIA maximum glacier geometry. Mass balance modelling is based on observed temperature records from the region, along with the winter Pacific Decadal Oscillation index as a precipitation proxy. Reconstructions of glacier mass change inform estimates of meltwater runoff over the historical period, and model calibration from the LIA and 20th-century reconstructions will aid in future projections of the effects of climate change on glacier recession. Furthermore, the model developed will be effective for further future studies with ensembles of glaciers.