A topographic and photogrammetric study of rock glaciers in the southern Yukon Territory

Abstract

This research statistically examined the topographic characteristics of rock glacier locations in the Yukon Territory and tested the suitability of the Canadian air photo collection for photogrammetrically measuring rock glacier velocities. A database of more than 1500 rock glacier locations in the Yukon was compiled. The topographic characteristics of rock glaciers in a 12% sample were compared by classifying the sample by morphology (lobate or tongue-shaped) and activity (active, inactive or relict) and testing the difference between the class properties of elevation, slope, aspect and area. Tongue-shaped rock glaciers occurred at significantly higher mean and minimum elevations than lobate forms. Active rock glaciers were significantly larger than inactive and relict forms, and active forms were significantly more north-facing than inactive forms. The photogrammetry study found that it is possible to measure rock glacier movement rates from multi-temporal air photos of the quality and frequency available for the Canadian North. It was also found that thermokarst development could be tracked on multi-temporal air photos, though its presence hinders the measurement of movement. With the continued acquisition of high quality photos, the technique should prove useful for monitoring both rock glacier movement and thermokarst development.