Else Kolstrup

Changes in palsa distribution in relation to climate change in Laivadalen, Northern Sweden, especially 1960-1997.

Changes in the distribution of palsas in Swedens most southerly major palsa bog are outlined from 1960 to 1997 using aerial photographs taken in 1960 and 1976 as well as a study reported in a publ ...

Chemical denudation in arctic-alpine Latnjavagge (Swedish Lapland) in relation to regolith as assessed by radio magnetotelluric-geophysical profiles

Chemical denudation in arctic-alpine Latnjavagge (Swedish Lappland) in relation to regolith as assessed by radio magnetotelluric-geophysical profiles.

Water chemistry and its diversity in relation to local factors in the Latnjavagge drainage basin, arctic¿oceanic Swedish Lapland

The chemistry of precipitation, snow pack and surface water has been analysed on 205 samples collected during the 2001 field season at 25 selected sites within the Latnjavagge drainage basin in arctic–oceanic northern Swedish Lapland. Additionally, daily discharge and yield of dissolved solids have been calculated for several subcatchments and the entire Latnjavagge catchment during the years 2000, 2001 and 2002. Chemical water analysis included the components Ca2+, Mg2+, Na+, K+, Fe2+, Mn2+, Cl−, NO3−, SO42− and PO43−, with SO42− and Ca2+ being the dominant ones in the surface water. Solute concentrations and chemical denudation were low, but showed significant differences within the basin. In areas of shade, longer snow cover, frozen ground and thin regolith, concentrations over the summer were perceptible but so low that solutes brought into the basin from precipitation could be detected in the surface water. In one locality, it was even found that lake water could reflect snowmelt to such an extent that the solute concentration was less than that of summer precipitation. The highest concentrations were found at a radiation-exposed, W-facing, vegetated, moderately steep slope with relatively thick regolith that was thawed at the time of snowmelt in early June. In such well-drained sites with continuous subsurface water flow, a maximum of contact between water and mineral particles could take place. The concentration values revealed differences in the rate of thawing of frozen ground between shaded areas and/or areas at higher altitude on the one hand and radiation-exposed areas on the other. A comparison with published results from Karkevagge a few kilometres to the northwest as well as from other periglacial locations indicates that the chemical denudation values from Latnjavagge are more representative of periglacial oceanic environments than the values from the Karkevagge catchment, which shows especially high chemical denudation rates. The investigation in Latnjavagge stresses the importance of spatial variability within even small catchments of homogeneous lithology as it demonstrates that solute concentrations from different subbasins can differ substantially dependent on exposure to radiation, duration of snow cover and frozen ground conditions, regolith thickness and possibly also to vegetation cover and slope angle as factors steering water turbulence and retention of drainage.

Late Magdalenian feminine flint plaquettes from Poland

The remains of a hunting site dated to 15000 years ago, captured in an ice wedge, included woolly rhinoceros, horse and arctic fox. Also present were 30 flint plaquettes with curvy feminine outlines. The authors show that these unworn flint profiles can be assigned to a canon of Magdalenian art that extends over much of northern Europe.

Palsa Development and Associated Vegetation in Northern Sweden

Abstract Palsas in all stages of growth and decay were investigated for vegetation, snow depth, and thaw depth in summer in four bogs in northern Sweden. A field classification of successive palsa stages was developed based on palsa vegetation composition and morphology. The initial phase of the aggrading stage is characterized by low mound forms and vegetation with the same hydrophilous composition as in the bog, but somewhat dried out. In the stage of continued aggradation Betula nana colonizes from the surroundings and hydrophilous vegetation is poorly represented in the higher parts even though the mounds are still low. Stable palsas, which are usually the tallest mounds, have vegetation that tolerates drier conditions; Empetrum hermaphroditum is the vascular species with the highest coverage at this stage. Decay starts with block erosion and melting of the mound forms. Degrading palsas have taller shrub vegetation that causes significantly thicker snow reducing heat loss from the core in winter. Conversely, the shrub vegetation has a dampening effect on penetration of heat into the mounds in summer. The degraded stage bears no morphological resemblance to the mounds, but at this stage there is a higher diversity of species owing to additional moist and wet growing sites.

56 YEARS OF SOLIFLUCTION MEASUREMENTS IN THE ABISKO MOUNTAINS, NORTHERN SWEDEN – ANALYSIS OF TEMPORAL AND SPATIAL VARIATIONS OF SLOW SOIL SURFACE MOVEMENT

Abstract. Solifluction movement rates from 1952 to 2008 for the Abisko region, northern Sweden, have been compiled and analysed through correlation tests and multiple regression. The temporal analysis is based on two datasets (Lobe11 & gridAB and Line B) from Kärkevagge. The dataset Lobe11 & gridAB show a strong correlation between movement rates and mean annual air temperature (MAAT) and MAAT is also identified as one of the significant contributing parameters in the multiple regression model. No significant correlations were found for the Line B dataset. The spatial analysis indicates generally higher movement rates in the western part of the region and at lower altitudes mainly between 700 and 900 m a.s.l., but the spatial variability is high. To reduce the influence of the temporal variation the data for the correlation tests of the spatial variations were divided into two parts: 1957 to 1980 and 1981 to 2008. The correlation analysis of the dataset 1957 to 1980 shows a significant negative correlation between annual average movement rates and permafrost probability and altitude. The dataset 1981 to 2008 shows a positive correlation between movement rates and wetness index. It is concluded that movement rates may increase with higher MAAT in the western part of the region (Kärkevagge), the spatial variability of movement rates within the region is very high and that altitude (and/or permafrost) together with wetness index are the main controls on the regional spatial variation. The study highlights the limitations in establishing statistical relationships between movement rates and climate using data from different field empirical studies.

Experimental weathering of selected non-calcareous rock types under wet/moist conditions

This thesis presents a method for detailed landscape presentation. The method incorporates both fieldwork-based comprehensive geomorphological description and digital data handling and thus contributes in filling the gap between traditional geomorphological mapping and modern geomorphological studies performed in Geographic Information Systems (GIS).The main part of the thesis relates to development of a new detailed geomorphological mapping system, constructed to be easy to use and yet present a large amount of geomorphological information. The legend of the mapping system has successfully been applied to various types of landscapes, mapped at various scales between 1:5,000 and 1:50,000 without any modifications needed. The information presented in the map is based on simple descriptive criteria and thus the subjectivity is kept low, which enables a broad field of usage. In parallel with the mapping system a GIS-based geomorphological database has been developed. The structure and data presentation of the new mapping system allows for easy transformation of the data to form part of this database. The selected format of the GIS database is the ESRI ArcGIS®, Personal geodatabase.In the development of the geomorphological mapping system four field areas have been mapped in central (Bonas, Risa and Liden) and northern Sweden (Tarfala). In addition the new legend has been adapted to a field area situated in Vorarlberg, Austria (Upper Gamperdona valley).In relation to the Tarfala field area an added issue of the project has been to give insights in the effects of physical and chemical weathering on various rock types to see if this can be detected in materials and landforms. The results from this study point at that resistance towards weathering vary among rocks even though they are of same rock type.

Detailed geomorphological mapping: A potential basis for sediment flux assessments

A detailed geomorphologic map of the Vattholma area, Uppland, Sweden, uses a newly developed legend that allows visual presentation of much descriptive information on hydrography, morphometry and morphography, lithological composition as well as genesis of the landforms. The area consists of an old peneplane with a rift valley and has undergone several glaciations. Following the last glaciation, glacio-isostatic rebound transformed the area from sea bottom to dry land, and today the major impression is one of glacially modified higher areas and lower lying marine/lacustrine parts. The geomorphological map provides information on the extension and relative distribution of lithologies and demonstrates how the landscape appears today and outlines the processes, which have created the landforms through time. In combination with regolith depth data the map gives a good overview of the area. It is suggested that this type of map can provide important background information for the choice of sampling and monitoring sites and for modelling purposes of both physical and chemical changes of the landscape. The system also works in cold climate areas in agreement with the focus of the sediflux program.