Using Landsat 7 ETM+ imagery and Digital Terrain Models for mapping glacial lineaments on former ice sheet beds

In this paper, we consider the application of Landsat 7 ETM+ imagery and Digital Terrain Models (DTM) for mapping glacial lineaments in a formerly glaciated area of Wales. A series of landform interpretation experiments were conducted using different false colour composites (FCC) and a DTM, both individually and in combination. The experiments indicate that the optimal FCC for detection of glacial lineaments at this scale includes the thermal-infrared (TIR) band. However, by performing the interpretation both in the TIR composite and in a visible and near-infrared (VNIR, bands 4, 3, and 2) draped over the DTM, we were able to substantially increase the number of lineaments identified. The glacial lineaments consist of fractured bedrock and are defined as rock drumlins. The landform system formed by these rock drumlins is characterized by convergent flow patterns at its head, attenuated lineaments, and abrupt lateral margins, which may indicate formation by fast-flowing ice.