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Number of results: 10
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Abstract

Three types of rock glaciers (moraine, cirque and subslope ones) were distinguished in northwestern Wedel Jarlsberg Land. Subslope rock glaciers were found different from nival moraines. A development of subslope and fossil cirque rock glaciers was connected with the older Holocene whereas of active cirque and moraine rock glaciers with the Little Ice Age.
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Abstract

Although the terrestrial marginal zones of some glaciers on Spitsbergen are relatively well described, we are largely ignorant about the morphology of their submarine forefields. Initial reconnaissance of the forefields of the Aavatsmark and Dahl glaciers in the Kaffiøyra region and soundings made in that of the Hans Glacier (southern Spitsbergen ) indicate the occurrence of sea-floor push-moraines which can be as much as 3 m high. Their lateral separation is considered to denote annual recession rates. They appear to result from cyclical annual advances of ice-cliffs during winters when the deposits are risen up at the contact of the ice with the sea-floor. The development of the major forms may be related to surge. There is some evidence that certain elements in the sea-bed morphology date from the Little Ice Age (LIA).
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Abstract

Water bears (Tardigrada) are known as one of the most extremophile animals in the world. They inhabit environments from the deepest parts of the oceans up to the highest mountains. One of the most extreme and still poorly studied habitats which tardigrades inhabit are cryoconite holes. We analysed the relation between area, depth, elevation and tardigrades densities in cryoconite holes on four glaciers on Spitsbergen. The mean (±SD) of cryoconite area was 1287.21±2400.8 cm2, while the depth was on average 10.8±11.2 cm, the elevation 172.6±109.66 m a.s.l., and tardigrade density 24.9±33.0 individuals per gram of wet material (n = 38). The densities of tardigrades on Hans Glacier reached values of up to 168 ind. cm3, 104 ind. g-1 wet weight, and 275 ind. g-1 dry weight. The densities of tardigrades of the three glaciers in Billefjorden were up to 82 ind. cm2, 326 ind. g-1 wet weight and 624 ind. g-1 dry weight. Surprisingly, although the model included area, depth and elevation as independent variables, it cannot explain Tardigrada density in cryoconite holes. We propose that due to the rapid melting of the glacier surface in the Arctic, the constant flushing of cryoconite sediments, and inter-hole water-sediment mixing, the functioning of these ecosystems is disrupted. We conclude that cryoconite holes are dynamic ecosystems for microinvertebrates in the Arctic.
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Abstract

The near-surface ice thermal structure of the Waldemarbreen, a 2.5-square km glacier located at 78°N 12°E in Spitsbergen, Svalbard , is described here. Traditional glaciological mass balance measurements by stake readings and snow surveying have been conducted annually since 1996. The near-surface ice temperature was investigated with automatic borehole thermistors in the ablation and accumulation areas in 2007-2008. The mean annual surface ice temperatures (September-June) of the ablation area were determined to be -4.7°C at 1 m depth and -2.5°C at 9 m . For the accumulation area, they were -3.0°C at 2 m , and -2.3°C at 10 m depth between September and August. On the Waldemarbreen, at 10 m depth, the mean annual near-surface ice temperature was 4.0°C above the mean annual air temperature in the accumulation area. The Waldemarbreen may thus be classified as a polythermal type with cold ice which is below the pressure melting point and a temperate ice layer in the bottom sections of the glacier and with a temperate surface layer only during summer seasons. At a depth of 10 m , temperatures are of the order of -2°C to -3°C.
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Abstract

The purpose of this study is to describe the current state of tidewater glaciers in Svalbard as an extension of the inventory of Hagen et al. (1993). The ice masses of Svalbard cover an area of ca 36 600 km2 and more than 60% of the glaciated areas are glaciers which terminate in the sea at calving ice-cliffs. Recent data on the geometry of glacier tongues, their flow velocities and front position changes have been extracted from ASTER images acquired from 2000-2006 using automated methods of satellite image analysis. Analyses have shown that 163 Svalbard glaciers are of tidewater type (having contact with the ocean) and the total length of their calving ice-cliffs is 860 km . When compared with the previous inventory, 14 glaciers retreated from the ocean to the land over a 30-40 year period. Eleven formerly land-based glaciers now terminate in the sea. A new method of assessing the dynamic state of glaciers, based on patterns of frontal crevassing, has been developed. Tidewater glacier termini are divided into four groups on the basis of differences in crevasse patterns and flow velocity: (1) very slow or stagnant glaciers, (2) slow-flowing glaciers, (3) fast-flowing glaciers, (4) surging glaciers (in the active phase) and fast ice streams. This classification has enabled us to estimate total calving flux from Svalbard glaciers with an accuracy appreciably higher than that of previous attempts. Mass loss due to calving from the whole archipelago (excluding Kvitřya) is estimated to be 5.0-8.4 km3 yr-1 (water equivalent - w.e.), with a mean value 6.75 ± 1.7 km3 yr-1 (w.e.). Thus, ablation due to calving contributes as much as 17-25% (with a mean value 21%) to the overall mass loss from Svalbard glaciers. By implication, the contribution of Svalbard iceberg flux to sea-level rise amounts to ca 0.02 mm yr-1. Also calving flux in the Arctic has been considered and the highest annual specific mass balance attributable to iceberg calving has been found for Svalbard.
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Abstract

Marine rock-accumulative terraces at 2-230 m a.s.l. in the southern Sörkapp Land are typical for glacioisostaticly uplifted areas. The Holocene terraces reach up to 19 m a.s.l. An outstanding coastal ridge at 9-10 m a.s.l. was radiocarbon-dated at 6580±160 years B.P. No marine transgression during the Holocene on higher and older terraces was noted, what is also confirmed by well preserved raised storm ridges. Any of glacial advances during the Holocene were more extensive than the one of the Little Ice Age. However the Pleistocene glaciations were more extensive. Among glacial landforms in the area there are: ice-cored frontal and lateral moraines up to 70 m high, plains of ground, ablation and fluted moraines, complexes of glaciofluvial fans. The glaciers retreated 0.3-2 km since 1936 i.e. ca 10 m a year on the average. There are large consequent structural landslides on eastern slopes of Keilhaufjellet.
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Abstract

Reduced ice thickness made the glaciers of the northeastern Sörkapp Land occupy considerably smaller area in 1971 than in 1961. Glacial retreat was however more limited in this area than in a remaining part of the Sörkapp Land. Melting of firn intensified processes on mountain slopes.
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Abstract

Arctic glaciers respond quickly to climatic conditions, which is why they play a special role as climate warming indicators. Studying them in the long term is the key to understanding future global environmental changes.
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Abstract

Arctic glaciers depend on supply of moisture, mostly from the Atlantic. The snowline is remarkably high in northeast Siberia, remote from this source. Because of differential solar radiation receipt, local glaciers have a northward−facing tendency throughout the Arctic. This is weaker than in dry mid−latitudes but low sun angles enhance the effects of shading, compensating for the broader range of aspects ( i.e. slope directions) illuminated in summer. Statistics from the World Glacier Inventory and other sources show that mass balance differences between slopes of different aspects give both more glaciers, and lower glaciers, facing the favoured direction: usually North. This is clear, for example, for local glaciers (and for all small glaciers) in central Spitsbergen and in Axel Heiberg Island. Wind effects (drifting snow to leeward slopes) are much less important, except in northwest Europe from Norway to Novaya Zemlya which is under the strong influence of westerly winds, greatest in the Polar and Sub−polar Urals. A thorough analysis is provided of aspect data for local glaciers within and near the Arctic Circle, and of variation in glacier mid−altitude with aspect and position. There is consistency between mean glacier aspect (in terms of numbers) and aspect with lowest glaciers, everywhere except in Wrangel Island.
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Abstract

Soils, having a well-developed sequence of A and Bw horizons, are widespread on the uplifted marine terrace 8- 12 m a.s.l. in the proximity of Nottinghambukta Bay . The present-day origin of these soils is however questionable, while similarly developed soils, but buried under the cover of the youngest till were found on a forefield of the Werenskiold Glacier. To quantify an intensity of the soil-forming process under present climate conditions of SW Spitsbergen , the chronosequence of soils developed from the Recent, up to 70 year-old moraines, was studied on the forefield of Werenskiold Glacier. Significant dissolution of CaCO3, decrease of pH, leaching of calcium and magnesium, increase of amorphous iron content, as well as an accumulation of organic matter and initial formation of aggregate soil structure were observed within the surface layer of recent till. The 70 year-long period of pedogenesis was, however, too short for a distinct morphological differentiation of the subsurface B horizon. It is concluded, that deep and structural Bw horizons of some surface and buried soils are relicts of a much longer period of relatively warm climate before the last transgression of glaciers.
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