| A coherent pattern of subglacial landforms in southeast Alberta form an erosional landform continuum. Scoured bedrock tracts, flutes and transverse bedforms may have been produced by turbulent, subglacial sheet flows during the Livingstone Lake flood event. Tunnel channels are interpreted as products of erosion by catastrophic, channelised drainage beneath the Laurentide Ice Sheet. Transverse bedforms are interpreted as bedrock ridges modified by erosion beneath stationary waves in subglacial meltwater flows and are identical to antidunes produced by rivers. A one-dimensional hydraulic model of subglacial flow through the tunnel channel network calculates the discharge, velocity and Reynolds Numbers required for flow through channels with convex-up long profiles. Flow will occur when hydraulic head exceeds 910 m to 950 m, for the Lost River and Sage Creek channels, respectively. Maximum discharge that can be carried by the network is 10... |
