Landform signature of the Laurentide and Cordilleran ice sheets across Alberta during the last glaciation

Atkinson, Nigel; Utting, D J; Pawley, Steven

doi:10.1139/cjes-2014-0112

Cited by 30 publications

(43 citation statements)

References 53 publications

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“…The texture of each mapped surficial geology unit was defined as being coarse or fine from the primary texture classification if available (coarse = gravel, sand, sandy‐gravel, silty‐sand, silty‐gravel; fine = silt, clay, sand‐silt‐clay, sandy‐silt, sandy‐clay, silty‐clay, clayey‐silt). If no primary texture was provided, geomorphic class and landform genesis were used (Atkinson, Utting, & Pawley, ; Fenton et al ., ); fluvial, glacial‐fluvial, aeolian, and littoral glacio‐lacustrine landforms were combined for coarse HRAs (%Coarse) . The fine‐textured percentage cover (%Fine ) was equal to 100 ‐%Coarse .…”

Section: Methodsmentioning

confidence: 99%

Landscape controls on long‐term runoff in subhumid heterogeneous Boreal Plains catchments

Devito

Hokanson

Moore

et al. 2017

Hydrological Processes

122

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We compared median runoff (R) and precipitation (P) relationships over 25 years from 20 mesoscale (50 to 5,000 km2) catchments on the Boreal Plains, Alberta, Canada, to understand controls on water sink and source dynamics in water‐limited, low‐relief northern environments. Long‐term catchment R and runoff efficiency (RP−1) were low and varied spatially by over an order of magnitude (3 to 119 mm/year, 1 to 27%). Intercatchment differences were not associated with small variations in climate. The partitioning of P into evapotranspiration (ET) and R instead reflected the interplay between underlying glacial deposit texture, overlying soil‐vegetation land cover, and regional slope. Correlation and principal component analyses results show that peatland‐swamp wetlands were the major source areas of water. The lowest estimates of median annual catchment ET (321 to 395 mm) and greatest R (60 to 119 mm, 13 to 27% of P) were observed in low‐relief, peatland‐swamp dominated catchments, within both fine‐textured clay‐plain and coarse‐textured glacial deposits. In contrast, open‐water wetlands and deciduous‐mixedwood forest land covers acted as water sinks, and less catchment R was observed with increases in proportional coverage of these land covers. In catchments dominated by hummocky moraines, long‐term runoff was restricted to 10 mm/year, or 2% of P. This reflects the poor surface‐drainage networks and slightly greater regional slope of the fine‐textured glacial deposit, coupled with the large soil‐water and depression storage and higher actual ET of associated shallow open‐water marsh wetland and deciduous‐forest land covers. This intercatchment study enhances current conceptual frameworks for predicting water yield in the Boreal Plains based on the sink and source functions of glacial landforms and soil‐vegetation land covers. It offers the capability within this hydro‐geoclimatic region to design reclaimed catchments with desired hydrological functionality and associated tolerances to climate or land‐use changes and inform land management decisions based on effective catchment‐scale conceptual understanding.

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Section: Methodsmentioning

confidence: 99%

Landscape controls on long‐term runoff in subhumid heterogeneous Boreal Plains catchments

Devito

Hokanson

Moore

et al. 2017

Hydrological Processes

122

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“…To analyze and compare topographic patterns as functions of wavelength and amplitude (i.e., spectra), we compiled 22, 10 × 10 km digital topographic models (DTMs) from 5 environmental settings, including the seafloor of formerly glaciated continental shelves [ Ó Cofaigh et al , ; Dowdeswell et al , ; Larter et al , ; Anderson et al , ; Jakobsson et al , ; Livingstone et al , , , ] and terrestrial landscapes [ Atkinson et al , ; Margold et al , , ] as well as one modern ice stream bed [ King et al , ]. Half of these areas contain MSGLs.…”

Section: Methodsmentioning

confidence: 99%

The periodic topography of ice stream beds: Insights from the Fourier spectra of mega‐scale glacial lineations

et al. 2017

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Ice stream bed topography contains key evidence for the ways ice streams interact with, and are potentially controlled by, their beds. Here we present the first application of two‐dimensional Fourier analysis to 22 marine and terrestrial topographies from 5 regions in Antarctica and Canada, with and without mega‐scale glacial lineations (MSGLs). We find that the topography of MSGL‐rich ice stream sedimentary beds is characterized by multiple, periodic wavelengths between 300 and 1200 m and amplitudes from decimeters to a few meters. This periodic topography is consistent with the idea that instability is a key element to the formation of MSGL bedforms. Dominant wavelengths vary among locations and, on one paleo ice stream bed, increase along the direction of ice flow by 1.7 ± 0.52% km−1. We suggest that these changes are likely to reflect pattern evolution via downstream wavelength coarsening, even under potentially steady ice stream geometry and flow conditions. The amplitude of MSGLs is smaller than that of other fluvial and glacial topographies but within the same order of magnitude. However, MSGLs are a striking component of ice stream beds because the topographic amplitude of features not aligned with ice flow is reduced by an order of magnitude relative to those oriented with the flow direction. This study represents the first attempt to automatically derive the spectral signatures of MSGLs. It highlights the plausibility of identifying these landform assemblages using automated techniques and provides a benchmark for numerical models of ice stream flow and subglacial landscape evolution.

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“…To better understand why vegetation sensitivity to prolonged drought might exist in some areas and not in others, we incorporated additional geospatial indicators that have known influences on local hydrology as hydrological response units (HRUs; Devito et al, ). These include (a) detailed surficial geology and soil texture maps (Atkinson et al, ; Fenton et al, ), (b) local topographic derivatives including topographic variance (an indicator of surface roughness) and slope, derived from ASTER Global Digital Elevation Model (https://gdex.cr.usgs.gov/gdex/), and (c) land cover type (Table ). Areas that have undergone previous disturbance (e.g., harvesting and wildfire) were excluded from this comparison.…”

Section: Methodsmentioning

confidence: 99%

“…Approximately 70% of P falls within the April to August period, peaking in June/July associated with convective storms (Downing & Pettapiece, ). Watersheds are composed of extensive wetlands, dominated by peatlands (20–80%), and are characterized by fine‐grained distal and aeolian sediments, and glaciolacustrine deposits (Table ; Atkinson, Utting, & Pawley, ). Surface active layer organic soils in these regions typically have higher saturated hydraulic conductivity (low hydraulic conductivity in deeper peats) than till and fine‐grained sediments, alternating ground water movement between till moraine and low‐relief wetland areas (Thompson et al, ).…”

Section: Study Areamentioning

confidence: 99%

“…Surface active layer organic soils in these regions typically have higher saturated hydraulic conductivity (low hydraulic conductivity in deeper peats) than till and fine‐grained sediments, alternating ground water movement between till moraine and low‐relief wetland areas (Thompson et al, ). Low‐relief areas are composed primarily of stunted black spruce ( Picea mariana ), Labrador tea ( Ledum groenlandicum ), and Sphagnum moss vegetation, often associated with poorly drained, organic soils (Table ; Atkinson et al, ). Ice cored and till moraines of CMw watersheds are covered by a mixture of conifer (white spruce [ Picea glauca ], balsam fir [ Abies balsemea ], lodgepole [ Pinus contorta ], and jack pine [ Pinus banksiana ]) forests found on coarse‐textured soils, whereas deciduous species (primarily trembling aspen [ Populus tremuloides ] and white birch [ Betula papyrifera ]) are found on fine‐texture soils.…”

Section: Study Areamentioning

confidence: 99%

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Remote sensing of ecosystem trajectories as a proxy indicator for watershed water balance

et al. 2018

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Ecosystem trajectories are inextricably linked to hydrology; however, water availability is not easily observed within the landscape. The response of vegetation to soil water availability may provide an indicator of local hydrology and the resilience or sensitivity of ecosystems to long‐term changes in water balance. In this study, vegetation trajectories derived from Landsat Modified Soil Adjusted Vegetation Index over a 22‐year period are used as an indicator of spatio‐temporal changes of watershed water balance and surface water storage within 6 proximal watersheds of the Boreal Plains ecozone of Alberta, Canada. The interactions between hydrology, topography, geology, and land cover type are examined as they relate to vegetation change. In this study, we find that run‐off ratio (run‐off/precipitation) is greater within watersheds with greater variability of relief, compared within subhumid, wetland‐dominated watersheds (average = 0.35, 0.20, respectively), which experience lagged run‐off response. A 2‐year drought had a greater impact on vegetation trajectories within variable relief watersheds containing a high proportion of coarse‐grain surficial geology, compared with peatland‐dominated watersheds. The drought extended for an additional 1 to 2 years within 3 subhumid watersheds, reducing watershed run‐off to less than 50 mm per water year (November to October) in 2 watersheds. However, proportional area of decline of Modified Soil Adjusted Vegetation Index was significantly less within these watersheds. The results of this study indicate that wetlands play an important role for local water balance and ecosystem maintenance during periods of water stress and should be considered within land use planning and reclamation strategies of the Boreal Plains.

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Landform signature of the Laurentide and Cordilleran ice sheets across Alberta during the last glaciation

Cited by 30 publications

References 53 publications

Landscape controls on long‐term runoff in subhumid heterogeneous Boreal Plains catchments

Landscape controls on long‐term runoff in subhumid heterogeneous Boreal Plains catchments

The periodic topography of ice stream beds: Insights from the Fourier spectra of mega‐scale glacial lineations

Remote sensing of ecosystem trajectories as a proxy indicator for watershed water balance

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