Research on permafrost in the Abisko area of northern Sweden date from the 1950s. A mean annual air temperature of −3°C in the Abisko mountains (i.e. 1000 m a.s.l.) and −1°C beyond the mountain area at an altitude of around 400m suggests that both moun− tain and arctic permafrost occur there. Several geophysical surveys were performed by means of resistivity tomography (ERT) and electromagnetic mapping (EM). Wherever pos− sible the geophysical survey results were calibrated by digging tests pits. The results show that permafrost occurs extensively in the mountain areas, especially those above 900m a.s.l. and also sporadically at lower altitudes. At 400 m a.s.l. permafrost may be up to 30 m thick. Its thickness and extent are determined largely by the very variable local rock and soil con− ditions. Fossil permafrost is also likely to occur in this area.
Preliminary results of hydrological investigations carried through at southern shore of Bellsund are presented. Negative meltwater budget of the permafrost was noted for summer 1986. Temperature and total mineralization of waters are varied in space. Temperature of outflowing meltwaters is related to air temperature. Diurnal rhythm of temperature has been distinguished in springs.
Humic substances are polydisperse mixtures of structurally complex matters with different molecular weights. The complexity of molecular composition of humic substances is reflected through their physical and chemical properties and results in diverse interactions both with inorganic components and living organisms. The correlation of the molecular composition of humic and fulvic acids and their molecular weight distribution were analyzed by means of CP/MAS 13C NMR spectroscopy and size exclusion chromatography. Humic acids are a dynamic system containing macromolecular, oligomeric and low-molecular components. Fulvic acids are a monodisperse mixture of relatively low-molecular (up to 2 kDa) organic compounds. A significant correlation between the content of high and medium weight molecular fractions with labile fragments and low molecular weight fractions with hydrophobous fragments of humic acids has been revealed.
Data on the molecular structure of humic substances (HSs) of zonal soils for the southern, middle, northern taiga and southern tundra of northeastern European Russia have been obtained. This was accomplished using solid-state 13C nuclear magnetic resonance (13C NMR) technique. The soils under study vary in the point of genesis and degree of hydromorphism. The impact of environmental factors (temperature and humidity) on qualitative and quantitative composition of humic (HAs) and fulvic acids (FAs) has been determined. Excess moisture significantly affects HS accumulation and HS molecular structure: hydromorphic taiga soils accumulate HSs enriched by unoxidized aliphatic fragments, tundra soils – the ones enriched by carbohydrate fragments. Various conditions of soil genesis predefine the specific character of structural and functional parameters of HSs in the southern taiga to southern tundra soils, as is expressed through the increased portion of labile carbohydrate and amino acid fragments and methoxyl groups within the structure of HSs. The tundra humification is characterized by levelling-off of structural and functional parameters of major classes of specific organic compounds of soils – HAs and FAs.
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.