Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 7
items per page: 25 50 75
Sort by:

Abstract

Mineralogical and chemical analysis of the glacial deposits of the Petuniabukta region, laid down due to glacial advances occurring from the Billefjorden Stage to the Little Ice Age has been made. The deposits have substantial carbonate contents which, however, vary depending on rock types of which the bedrock is built up. The calcium ion is the main component of the sorption complex of the deposits under investigation. A proportion of other ions, including magnesium, sodium and potassium, is markedly lower. An increase in the magnesium, sodium and potassium ion contents of the sorption complex with age and a concurrent decline in calcium ions have been reported from glacial tills. The illite clay minerals prevail in glacial deposits occurring around Petuniabukta. Apart from them, there are large quantities of the chlorite and kaolinite clay minerals. The glacial deposits of Spitsbergen remain markedly richer in the chlorite group than glacial tills of Poland. Simultaneously, they contain markedly smaller amounts of minerals of the- smectite group and illite/smectite mixed-layer minerals. This is due to a fainter effect of the weathering processes on the glacial deposits of Spitsbergen, compared with the glacial tills of Poland.
Go to article

Abstract

Movement is one of the most spectacular phenomena involving glaciers. Deter- mining glacier surface velocity is now a routine aspect of glaciological studies. These are geodetic methods, especially satellite positioning, that most frequently is applied in such work. Using the Hans Glacier (SW Spitsbergen) as an example, the presented paper is an attempt at defining the time resolution limit of changes in the velocity determined using GPS positioning technology. A test network was established in the area of the examined glacier in order to define the size and variability of the main satellite positioning biases as well as to define their impact on determining position and the calculated velocity. A discussion relating to achieved accuracy (differentiated from measurement precision) for baselines of a length of several kilometres in the high latitudes has also been presented.
Go to article

Abstract

Hansbreen, a medium size tidewater glacier in Southern Spitsbergen (Svalbard) is one of the most intensively studied glaciers in the Arctic. This work presents new digital elevation models of its surface and basal topography based on data collected during GPS/GPR campaigns conducted in the spring seasons of 2005 and 2008, as well as on other recent topographic/bathymetric sources. The mean thickness of the glacier is calculated as 171 m and its volume is estimated to be 9.6 (±0.1) km 3 . The main feature of the bedrock morphology is a vast depression that is overdeepened below sea level and extends as far as 11 km upstream from the glacier front. This depression is divided into four individual basins by distinct sills that are related to the main geological/tectonic features of the area. The bedrock morphology affects considerably the glacier’s surface topography. The influence of bedrock and surface relief on the subglacial drainage system geometry is discussed. Vast depressions on the glacier surface favor concentration of meltwater and development of moulin systems.
Go to article

Abstract

The distribution of earthquake foci around the Hornsund fiord, south Spitsbergen, suggest the presence in this region of a micronode of geotectonic structures, exhibiting moderate dynamic activity. Dislocation description was applied to the processes of motion of the glacier and crack formation. Long-period seismic waves generated by the glacier-substratum dynamic system and impulses generates by icebergs seated on the sea bottom have been discussed.
Go to article

Abstract

This paper presents a detailed study of melting processes conducted on Hansbreen - a tidewater glacier terminating in the Hornsund fjord, Spitsbergen. The fieldwork was carried out from April to July 2010. The study included observations of meltwater distribution within snow profiles in different locations and determination of its penetration time to the glacier ice surface. In addition, the variability of the snow temperature and heat transfer within the snow cover were measured. The main objective concerns the impact of meltwater on the diversity of physical characteristics of the snow cover and its melting dynamics. The obtained results indicate a time delay between the beginning of the melting processes and meltwater reaching the ice surface. The time necessary for meltwater to percolate through the entire snowpack in both, the ablation zone and the equilibrium line zone amounted to c. 12 days, despite a much greater snow depth at the upper site. An elongated retention of meltwater in the lower part of the glacier was caused by a higher amount of icy layers (ice formations and melt-freeze crusts), resulting from winter thaws, which delayed water penetration. For this reason, a reconstruction of rain-on-snow events was carried out. Such results give new insight into the processes of the reactivation of the glacier drainage system and the release of freshwater into the sea after the winter period.
Go to article

Abstract

Hot point drills were carried through in the Hans Glacier (Spitsbergen). For that purpose a non-cored hot point drill of 700 wattage was constructed. It was used among others for installing the ablation-movement stakes, for hydrological observations and in the boreholes an ice temperature was controlled.
Go to article

Abstract

Investigations of the snow cover at the end of the winter 1990/1991 were carried out in several areas in West Spitsbergen, namely, Lomonosovfonna, Kongsvegen, Fridtjovbreen, Amundsenisen and that north of the Hornsund Fjord. The physical properties and chemical nature of precipitation and the snow cover were determined. The studies revealed high variation in the precipitation and the thickness of the snow cover: 317 mm w.e. (water equivalent) in the Hornsund area, 659 mm w.e. at Lomonosovfonna, 1076 mm w.e. at Fridtjovbreen and 1716 mm w.e. at Amundsenisen. The salt loads deposited in the snow cover in different parts of West Spitsbergen were also calculated (2.8 t/km2 at Lomonosovfonna, 15.8 t/km2 at Kongsvegen and 43.2 t/km2 at Amundsenisen). An intensive process of demineralisation during the conversion of snow to firn was revealed, reaching as much as 90% during the first summer. An attempt to determine the anthropogenic element content using the pH values for the precipitation and snow cover was also made. A distinct correlation between the physico-chemical characteristic of snow layer and falling snow was found. On the basis of the quality of the precipitation and snow cover, West Spitsbergen has been classified into following provinces: (1) northern situated within Arctic High (Lomonosovfonna and Kongsvegen), (2) southern ndergoing mainly moving air masses from the Arctic High and Greenland Low (Amundsenisen and Hornsund region).
Go to article

This page uses 'cookies'. Learn more