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 Kärkevagge 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 Kärkevagge 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.

This paper attempts to assess the role of chemical processes in the weathering, erosion, and denudation of periglacial alpine environments. It draws primarily from detailed chemical studies in the alpine zones of the Colorado Rocky Mountains, the Jotunheimen of Norway, and northwest Swedish Lapland. The nature or kind of chemical weathering processes has been found to be the same in periglacial environments as elsewhere. Comparison of weathering rates among various environments reveals periglacial chemical weathering to be generally slower than that in the tropical and temperate latitudes, but overlapping with the lower values reported from such environments. In broad terms, this statement is valid whether assessment is based on bedrock or regolith weathering estimates. Chemical weathering is found to be a substantial, sometimes the dominant, agent of mass removal in periglacial environments. Assessment of the role of chemical processes in denudation is complicated by the differing, sometimes conflicting, definitions of the term. It is important to view chemical processes primarily as a component of geomorphic work, rather than as an important land-forming agent, in periglacial environments. Given the intrinsic attribute of long distance transport out of a drainage basin implicit to denudation, chemical solute loads in periglacial river systems must be ranked highly in comparison to the, often dramatic, but nearly always highly localized contribution from alpine mass wasting. (c) 2004 Elsevier B.V. All rights reserved.

Periglacial landscapes comprise landforms that are inherently 3D structures, often exhibiting small-scale spatial heterogeneity of surface and subsurface conditions. The objectives of the present paper are to illustrate the potential of the novel application of 3D electrical resistivity imaging for mapping frozen ground conditions exemplified by three case studies with different geomorphological problems to be addressed and to consider the efficacy of the 3D approach to geomorphological investigations in mid-latitude high alpine and high latitude lowland permafrost environments. The approach described in the three case studies includes reconnaissance surveys using two-dimensional electrical resistivity tomography (2D ERT) followed by a detailed mapping using three-dimensional electrical resistivity imaging (3D ERI). The latter approach enables a spatial imaging of the subsurface resistivity distribution and clearly improves the delineation and characterization of subsurface structures compared to state-of-the-art 2D ERT that is limited to findings gained along single profiles or extrapolation between several profiles. Although it can be challenging and time-consuming to apply this technique in periglacial environments, the promising results demonstrate its value for the 3D delineation of frozen ground conditions. In the case of the described case study sites, characterizing the subsurface heterogeneity is close to impossible using drilling or 2D geophysical surveying alone because of the complex 3D nature of the frozen ground characteristics comprising permafrost and permafrost-free areas (alpine permafrost test site) as well as permafrost with variable characteristics (subarctic lowland permafrost test site) at close distance. Even in environments that seem homogeneous at first sight, this method allows us to detect substantial subsurface property variations that can be attributed to different frozen ground conditions. Furthermore, 3D ERI allows the linking of different data sources (e.g., site-specific geomorphology and hydrology) to enhance the spatial understanding of surface and subsurface characteristics and dynamics in permafrost environments. The improved knowledge of the geophysical anatomy and subsurface architecture of the permafrost occurrences revealed by this study suggests a more widespread use for glacial and periglacial landform studies in the future.

Frozen ground conditions and the geomorphological significance of contemporary permafrost have been assessed in a mountain environment south of Abisko, Sweden, using a combination of different methods including geomorphological mapping, near-surface temperature monitoring and 2D near-surface geophysics. The results confirm the existence of permafrost and related periglacial morphodynamics (e.g. gelifluction) for most of the upper parts of the investigation area (above 1200ma.s.l.). The middle parts form a transition zone with periglacial morphodynamics related to perennial and seasonal frost (gelifluction/solifluction) in combination with presently inactive periglacial landforms (ca. 1100 to 1200ma.s.l.). At lower altitudes recent morphodynamics are not related to contemporary permafrost conditions although landforms indicating the former impact of permafrost are present. The permafrost distribution is heterogeneous, showing a strong relationship to the distribution and duration of snow cover and surface textural characteristics. These factors together with the local hydrological conditions also determine the characteristics of the frozen ground. Multiple 2D electrical resistivity imaging surveys pointed to highly variable subsurface resistivity patterns corresponding to different frozen ground characteristics at close distance.

Environmental microbiology and advances in molecular techniques have been a driving force in advancing the understanding of microbial communities in previously understudied environments. Though it is widely accepted that biological and geological processes are closely linked, the importance of microbes in geomorphological processes has been understated. Microbes interact with the environment, playing a significant role in nutrient cycling, ion mobilization, and metal scavenging and concentration. Although in some of these areas understanding is expanding, the role of microbes in geochemical budgets in cold climates has been largely ignored. To investigate one such case of microbial influence, we focus on rock-coating development in the glacially eroded valley, Kärkevagge, in arctic-alpine Sweden. This bacterial diversity study shows evidence of a link between microbe–mineral interactions and key processes in the formation of diverse geochemical rock coatings. Here, we present a study of the bacterial role in metal scavenging and coating formation as a component of the geochemical budget of the valley.

Cryospheric events in the Arctic Ocean have been largely studied through the imprints of ice sheets, ice shelves and icebergs in the seafloor morphology and sediment stratigraphy. Subglacial morphologies have been identified in the shallowest regions of the Arctic Ocean, up to 1200 m water depth, revealing the extent and dynamics of Arctic ice sheets during the last glacial periods. However, less attention has been given to sedimentary features imaged in the vicinity of the ice-grounded areas. Detailed interpretation of the sparse available swath bathymetry and sub-bottom profiles from the Lomonosov Ridge and the Amundsen Basin shows the occurrence of mass transport deposits (MTDs) and sediment waves in the central Arctic Ocean. The waxing and waning ice sheets and shelves in the Arctic Ocean have influenced the distribution of MTDs in the vicinity of grounding-ice areas, i.e. along the crest of Lomonosov Ridge. Due to the potential of Arctic sediments to hold gas hydrates, their destabilization should not be ruled out as trigger for sediment instability. Sediment waves formed by the interaction of internal waves that propagate along water mass interfaces with the bathymetric barrier of Lomonosov Ridge. This work describes the distribution and formation mechanisms of MTDs and sediment waves in the central Arctic Ocean in relation to grounding ice and internal waves between water masses, respectively. The distribution of these features provides new insight into past cryospheric and oceanographic conditions of the central Arctic Ocean.