Eskers around the Keewatin Ice Divide: Northwest Territories and Nunavut

Major esker ridges as mapped by line symbology have been captured digitally for 113 1:250,000 scale NTS map sheets in the Northwest Territories and western mainland Nunavut, formally the districts of Mackenzie and Keewatin. The complete dataset has only been available in a generalized form via the 1:1,000,000 hardcopy release of Aylsworth and Shilts (1989). It is now available in a digital vector format with basic line segment attribution at the original 1:250,000 scale. Basic data validation indicates that there are only minor registration issues as compared against 1:250,000 topographic base data from CanVec and NTDB datasets. Comparison of the esker network against more recent, higher resolution esker mapping at 1:125,000 and 1:250,000 scale indicates that the esker network captured here represents the long dendritic and subparallel esker classes of Brennand (2000) relatively well, but underestimates the number of isolated short esker segments. The utility of the digital dataset has been demonstrated in its use as a training dataset for a quantitative esker mapping algorithm (Broscoe et al., 2011). It is a comparable dataset to other synoptic digital glacial landform datasets generated in recent years, for example Storrar & Stokes (2007); with the exception that this dataset focuses on one landform element, eskers.