GIS-MEDIATED REMOTE SPATIAL ANALYSIS OF RIBBED MORAINE MORPHOLOGY AND DISTRIBUTION WITHIN NORTHERN CANADA

Ribbed (a.k.a. Rogen) moraines are arcuate, subglacially-formed ridges oriented transverse to local palaeo-ice flow direction. Such features appear organized in fields, primarily throughout the former core-interior sectors of the Laurentide, British-Irish, and Fennoscandian Ice Sheets. Awareness of these landforms dates back well over a century, yet the process or processes responsible for their formation remain largely undetermined. Much research has endeavored to associate ribbed moraine genesis with specific subglacial ‘zones’ and their attendant basal ice flow regimes, though past efforts have lacked an explicit and reproducible means of assessing and comparing geomorphometric properties between discrete populations of landforms. More recent investigations incorporate geomatic techniques, and have contributed more generalizable insights, though the inherent spatial qualities of ribbed moraine fields have yet to be objectively examined. The current approach addresses these gaps by introducing quantitative measures of intra-field ribbed moraine distribution and morphology for three distinct locations within northern Canada. Continuous residual relief raster surfaces are derived from 0.75 arc-second Canadian Digital Elevation Data (CDED) digital elevation models (DEMs) and are used to digitize individual ribbed moraines directly into a geographic information system (GIS). High resolution (15 m, band 8 - panchromatic) Landsat 7 Enhanced Thematic Mapper Plus (ETM+) scenes are consulted as a secondary reference for feature verification and mapping in areas of particularly complex terrain. Morphometric parameters are calculated for digitized landforms using routine GIS measuring tools, and directional tendencies in feature incidence and certain attribute magnitudes are explored. Statistical measures of feature clustering, orientation, and parallel conformity are computed and presented as a quantitative basis for inter-field comparison of glacial landform distributions. Findings garnered by this research place more accurate constraints on regional ice flow history in northern Canada, and contribute new understandings to the vacillating literature on subglacial dynamics and landform genesis.