Short–Lived Damming of a High–Arctic Ice–Marginal Stream, Ellesmere Island, N.W.T., Canada

Abstract

AbstractThe discharge pattern of the “Schei River”, which drains a 91.2 km2 partly glacierized catchment on Ellesmere Island, is dominated by diurnal oscillations reflecting variations in the melt rate of snow and ice in the basin. Superimposed on this diurnal pattern are numerous short–lived discharge fluctuations of irregular periodicity and magnitude. The characteristics of such irregular fluctuations are described and attributed to periodic collapse of the glacier margin and concomitant damming of the main tributary of the “Schei River”. Collapse is initiated by the river undercutting the ice margin, and tends to be most frequent in the latter part of the flow season during periods of high discharge. Release of ponded water following the collapse of such ice dams may engender significant flood events.