Ice-Cliff Morphometry in Identifying the Surge Phenomenon of Tidewater Glaciers (Spitsbergen, Svalbard)

Abstract

In this study, 110 tidewater glaciers from Spitsbergen were studied to characterize the frontal zone using morphometric indicators. In addition, their time variability was also determined based on features of the active phase of glacier surges. Landsat satellite imagery and topographic maps were used for digitalization of the ice-cliffs line. In recent years (2014–2017) all the glaciers studied can be thus classified as: stagnant (33%), retreating and deeply recessing (33%), starting to move forward/fulfilling the frontal zone (23%), and surging (11%). Indicators of the glacier frontal zone (CfD and CfE) allow to identify the beginning and the end of the active phase through changes in their values by ca. 0.05–0.06 by the year and get even bigger for large glaciers as opposed to typical interannual differences within the limits of ff0.01 to 0.02. The active phase lasted an average of 6–10 years. The presence of a “glacier buttress system” and the “pointed arch” structure of the ice-cliff seem to be an important factor regulating the tidewater glacier stability.