GLACIAL KARST: AN INVESTIGATION OF SCALLOPED ICE CAVE WALLS, LLEWELLYN GLACIER, B.C. CANADA

An analysis of scallops on the walls of two subglacial drainage systems within in the Llewellyn glacier, B.C. Canada (an outlet glacier of the Juneau Icefield) was performed to validate the formation of ice-scallops as being related to that of limestone scallops. Scallop wavelength was compared with ice tunnel cross-sectional area and distance from the cave mouth. Average scallop wavelength was found to be positively correlated to cross-sectional area with a slope representing a 1.63 cm increase in wavelength for every 1.0 square meter increase in cross-sectional area. In contrast, average scallop wavelength was negatively correlated with distance from cave mouth, with a slope representing a decrease in wavelength by 0.74 cm for every additional 1.0 m from the mouth. The ice-scallops examined in this study were analogous to limestone scallops in their relationship to cross-sectional area, which represents formation caused by water turbulence with an inverse relationship between scallop size and water velocity. It appears, however that ice-scallops are also affected by melting due to the influence of warm atmospheric air entering the tunnel, as displayed by their enlargement near the mouth of the cave.