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Abstract

Complex analysis ofgeomorphological glacial processes in forefields of retreating glaciers in the southern Bellsund region was undertaken. Field studies and archival cartographic materials indicate continued glacial retreat, at least since the turn of the 19th and 20th centuries. Its average present rate of about 20 m/y is rather high and no moraine ridges are formed, except for the fluted moraines. Forefields of large glaciers are characterized by typical relief and sediments of frontal deglaciation only. Intensity and extent of glacial forefield remodelling depends mainly on activity ablation waters. At present glaciofluvial erosion predominates.
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Abstract

Twelve glaciers, representing various types, were investigated between 2000 and 2005, in a region adjacent to the northern reaches of Billefjorden, central Spitsbergen ( Svalbard ). On the basis of measurements taken using reference points, DGPS and GPS systems, analyses of aerial photographs and satellite images, geomorphological indicators and archival data their rates of deglaciation following the “Little Ice Age” (LIA) maximum were calculated variously on centennial, decadal and annual time scales. As most Svalbard glaciers have debris-covered snouts, a clean ice margin was measured in the absence of debris-free ice front. The retreat rates for both types of ice fronts were very similar. All studied glaciers have been retreating since the termination of the Little Ice Age at the end of 19th century. The fastest retreat rate was observed in the case of the Nordenskiöldbreen tidewater glacier (mean average linear retreat rate 35 m a-1). For land-terminating glaciers the rates were in range of 5 to 15 m a-1. Presumably owing to climate warming, most of the glacier retreat rates have increased several fold in recent decades. The secondary factors influencing the retreat rates have been identified as: water depth at the grounding line in the case of tidewater glaciers, surging history, altitude, shape and aspect of glacier margin, and bedrock relief. The retreat rates are similar to glaciers from other parts of Spitsbergen . Analyses of available data on glacier retreat rates in Svalbard have allowed us to distinguish four major types: very dynamic, surging tidewater glaciers with post-LIA retreat rates of between 100 and 220 m a-1, other tidewater glaciers receding of a rate of 15 to 70 m a-1, land terminating valley polythermal glaciers with an average retreat of 10 to 20 m a-1 and small, usually cold, glaciers with the retreat rates below 10 m a-1.
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Abstract

DC resistivity soundings and geomorphological surveys have been carried out in the marginal zones and adjacent outwash plains of two glaciers in central Spitsbergen, Norwegian Arctic: Ebbabreen and Hörbyebreen. The study has revealed complex relationships between landforms, buried glacier ice and permafrost. From this work it is possible to distinguish between moraine ridges which are ice-cored and those which are not. The latter occur in areas which have possibly been affected by glacier surge. The active layer thickness was found to be 0.4 to 2.5 m for diamicton deposits (moraines) and 0.3 to 1.6 m in outwash glacifluvial sediments. The sediment infill thickness in valleys was determined to be as much as 20 m, thereby demonstrating that sandurs have important role in sediment storage in a glacial system. Typical resistivity values for sediment types in both the active layer and in permafrost were also determined.
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Abstract

Geomorphological research based on geomorphological mapping seeks to identify the origins and age of forms as well as to describe the process that created or transformed a particular form. One of the most important aspects of this study is the morphometry and morphology of the landscape. This also applies to the submarine areas, and issues related to marine geomorphometry. Bathymetric data used in this study were obtained from the measurements of the Norwegian Hydrographic Service and measurements conducted by the authors. Its main goal was: to determine the bathymetry of the Recherchefjorden (Bellsund, Svalbard), establish morphometric parameters for the analysis of the morphology of the bottom. The boundaries of zones, related to the specific character of bottom geomorphology linked with geological structure, tectonics and, in particular, the impact of glacial system, was delineated. The sets of landforms (areas) were distinguished based on the morphometric analysis resulting from the determined parameters: slopes, its aspects, curvatures and Bathymetric Position Index. Basically, this areas are concentrated in two zones: the main Recherchefjorden and its surroundings. The delimitation also takes into account the origins and location of theme in relation to the glacial systems. On this basis, moraine areas were distinguished. They are linked with the Holocene advances of two glaciers, Renardbeen and Recherchebreen, mainly during the Little Ice Age. They constitute boundary zones between areas with different morphometric parameters: outer fjord and inner fjord. Moreover, taking into account geology and terrestrial geomorphology it was possible to describe paraglacial processes in this area.
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