ICE-MARGINAL CHARACTERISTICS OF FRIDTJOVBREEN (SVALBARD) DURING ITS RECENT SURGE

Fridtjovbreen is an actively surging tidewater glacier in western Spit sbergen, Svalbard. This paper presents observations made at the wester n flank of the glacier in July 199;, when the glacier front was still advancing rapidly and was characterised by steep lateral ice cliffs. T he geomorphological consequences of the surge include the formation of push moraines from toppled ice blocks along this ice cliff and the de velopment of debris-rich thrusts. There is also evidence of glaciotect onic deformation within deformed debris-rich thrusts. Thrusts are rest ricted to the lateral margins and are not seen in the terminal calving cliff. On its western flank, Fridtjovbreen is over-riding Sagabreen, a small-tributary glacier. Large facies variations in this area are a result of recycling by Fridtjovbreen of material originally transporte d as medial moraines on Sagabreen. There are few observations of landf orm development at actively surging glaciers in Svalbard. The Fridtjov breen descriptions pn,vide documentation for post-surge landform devel opment. More observations are required at the margins of actively surg ing glaciers to determine how representative Fridtjovbreen is of a sur ge event.