Survey of the Rusty Glacier Area, Yukon Territory, Canada, 1967–70

Abstract

A study of the movement of Rusty Glacier was undertaken and continued through four summers because it is believed to be a surging glacier in the last stages of the inactive phase preceding a surge. The entire glacier is very slow moving, essentially motionless in the lower third and most rapid in an area well above the firn line. Unusually steep flow-line emergence angles and higher than average longitudinal compression rates in the lower–middle part of the glacier indicate gradual thickening of the ice above the stagnant lower tongue. There is no clear correlation between local variations in flow rates and surface or bottom topography. The glacier is mostly colder than 0° C to the bottom, and in the one known area of 0° C bottom temperature, flow rates are not greater than elsewhere. Although the glacier is everywhere very thin, maximum flow rates seem clearly related only to variations in ice thickness. The nearby Trapridge Glacier is also a surging glacier and exhibits a strikingly similar flow pattern.

Hydraulic properties of subglacial sediment determined from the mechanical response of water-filled boreholes

“…As part of a long-term study of the cause and mechanics of glacier surging, we have, since 1989, recorded pressure fluctuations in both connected and unconnected holes at Trapridge Glacier, Yukon Territory, Canada. Previous investigations of this glacier have been reported by Collins (1972), Jarvis and Clarke (1975), Clarke and others (1984), Clarke and Blake (1991), Blake and others (1992) and Stone and Clarke (1993). The interpretation of natural and induced pressure fluctuations in connected boreholes was the focus of a recent thesis by Stone (1993) and the present work is concerned with interpretation of pressure fluctuations in unconnected holes.…”

“…Since 1980, more than 30 holes have been drilled to the bed in the warm-bedded part of Trapridge Glacier and instrumented with thermistor cables. There is no evidence of the presence of a basal temperate layer as encountered in classical polythermal glaciers (Clarke and others, 1984; Clarke and Blake, 1991). Trapridge Glacier ice is therefore assumed to be impermeable.…”

Structural Evolution During Cyclic Glacier Surges: 1. Structural Glaciology of Trapridge Glacier, Yukon, Canada

“…For the surface topography of the ice dynamics model we used the Natural Resources Canada 30‐m Digital Elevation Model (DEM). Elevation data were converted from the native Yukon Albers projection to a Zone 7 UTM projection with the NAD27 geodetic datum, the same projection used for Trapridge Glacier field work dating from 1967 (Collins, ) to 2007. Ice masks for 1951, 1970, 1972, 1977, and 1981 were produced from georeferenced vertical aerial photography (Frappé‐Sénéclauze, ) and the grid boundaries for the ice dynamics model were prescribed (green dashed outline in Figure b).…”

Slow surge of Trapridge Glacier, Yukon Territory, Canada

“…In the early 1970s, the thinning remnants of the receiving area known as the “apron” (zones C, D, and beyond) flowed at less than 1 m yr −1 , while the ice upglacier (zones A and B) was flowing at 10–15 m yr −1 . A zone of strongly emergent flow, resulting from the collision of active and inactive ice, was detected near the terminus [ Collins , 1972]. It was only in 1980, after a hiatus of 6 years in the field observations, that the morphologic consequences of these contrasting flow regimes became obvious: a wave‐like bulge had formed at the boundary between the two zones (Figures 2d and 2e).…”