Morphostructural zones of the Myrdalsjokull ice cap and its main outlet glacier the Hofdabrekkujokull, Iceland

The problem of the morphostructures of glaciers is directly associated, certainly as far as its condition and origin is concerned, with topographical, geomorphological and geological rock foundations, surrounding those at the bedrock of glaciers and also, in case of valley and outflow glaciers, with those of the valley slopes. differentiation of the bedrock of the Myrdalsjokull ice cap leads to a classification of its three morphostructural zones: the glaciomorphological centre (A) which has only slightly varied relief (a,- a4), a northern homogeneous macro-cone of radial flow (B), and a bipartite, supramarginal surrounding slope (C), which has a significant development of outflow glaciers. This differentiation of the subglacial relief and the rocky surrounding of the Hofdabrekkujokull, are manifested in the distribution of various types of foliation and fissuring on its subaerial surface. These, together with its hypsometric formation, were the basis for distinguishing four morphostructural zones of this glacier (Ht - H4). The distinctive morphostructural features of the sector of the bottom zone (H4) of the glacier determine the areas of its particular activity; this reflects the lithogenetic and morphogenetic nature of the subglacial bedrock. The deformed deposits of the bedrock and the nearest forefield represent an important dynamic effect of the glacial system.