Components of the Natural Environment

Abstract

Western Sørkapp Land geological structure is very varied. Pre-Quaternary bedrock consists of three complexes: (1) the most extensive rocks from the Middle Proterozoic to the Silurian, folded in the Caledonian Orogeny: dolomites, phyllites, schists, quartzites, limestones, sandstones, breccias, and others; (2) Early Carboniferous clastic sediments: sandstones, including quartzitic sandstones, siltstones, and shales; and (3) Triassic sedimentary rocks: sandstones and conglomerates. None of these complexes lies horizontally. Loose Quaternary deposits (marine, glacial, fluvial, organic, frost-weathering, slope, including talus and solifluction) are not continuous. The climate is Arctic and marine-type. Average annual temperatures vary from −9 to −3 °C there. Average annual precipitation totals reach 300–500 mm. The mountains in northwest Sørkapp Land remain free of glaciers due to their exposure to relatively warm and dry eastern foehn winds. All the lowlands are unglaciated too. Sørkapp Land glaciation is clearly Arctic-type for two reasons: the common presence of permafrost, and the very weak influence of altitude on the distribution and extent of glaciers. The principal landform types in western Sørkapp Land are coastal lowlands, mountains, and mountain valleys. Nonglacial rivers and lakes (supplied directly by atmospheric precipitation and an active layer of permafrost) play an important part. There are also karst springs and glacial rivers and lakes in the northeast and southeast of the study area. Typically for the High Arctic, the flora of western Sørkapp Land is dominated by cryptogams, mainly lichens—about 170 species—whereas vascular plant flora includes 82 species. Different vegetation types often create complex mosaics, following diverse habitat conditions (bedrock, terrain relief, hydrology, etc.). In a few places the presence of seabird colonies has a local but strong impact on the vegetation.