Subglacial landforms in northern Manitoba, Canada, based on remote sensing data

Abstract

Please click here to download the map associated with this article.

This paper presents a new subglacial landform map for northern Manitoba (58°-60° N). The region was formerly covered by the Laurentide Ice Sheet and is located at the southern margin of the Late Wisconsinan (∼25-10 Ka BP) deglacial Keewatin Ice Divide just west of Hudson Bay. Mapping was focused on determining the location and orientation of streamlined landforms (drumlins and megaflutes), Rogen moraines, and eskers for the 109,366 km² region. Based on the theory that landforms such as drumlins and Rogen moraines all result from subglacial ice flow processes, this map forms the basis for reconstruction of ice flow sets that indicate past glacial phases in northern Manitoba. It shows that the geomorphologic record, and hence ice flow history, is more complex than previously reported. There are several successive generations of ice flow indicators superimposed on top of each other, sometimes at abrupt (90°) angles.

Special attention is paid to the location and ridge crest orientation of Rogen moraines in northern Manitoba. Hence the map also provides insights into the characteristics of Rogen moraines in northern Manitoba, which are critical for investigating formative processes. 11,007 individual landforms were mapped using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) satellite imagery in combination with a Shuttle Radar Topography Mission (SRTM) digital elevation model and several SPOT 4 satellite images. The results are presented as a printable map at 1:1,125,000 scale.