Species and composition of tundra meadows

Observations of hummock and string-like microrelief features were made in High Arctic hydric meadows. Thermal shearing of thick bryophyte mats, and subsequent roll back during spring flooding appears to be one way in which this topography is formed. Hummocky and non-hummocky (flat) meadows show distinct floristic differences which may in part be due to observed differences in temperature, nutrient concentrations and moisture relations.

Geochemistry of sediments from the mid-oceanic Kolbeinsey Ridge

In order to assess recent submarine volcanic contributions to the sediments from the active Kolbeinsey Ridge, surface samples were analyzed chemically. The contribution of major and trace elements studied differ within the study area. A statistical analysis of the geochemical variables using factor analysis and cluster method allows to distinguish possible sample groups. Cluster method identifies three distinct sediment groups located in different areas of sedimentation. Group 1 is characterized by highest contents of Fe2O3, V, Co, Ni, Cu and Zn demonstrating the input of volcaniclastic material. Group 2 comprises high values of CaCO3, CaO and Sr representing biogenic carbonate. Group 3 is characterized by the elements K, Rb, Cs, La and Pb indicating the terrigenous component. The absolute percentage of the volcanic, biogenic and terrigenous components in the bulk sediments was calculated by using a normative sediment method. The highest volcanic component (> 60% on a carbonate free basis) is found on the ridge crest. The biogenic component is highest (10-30%) in the eastern part of the Spar Fracture Zone influenced by the East Iceland Current. Samples from the western and southeastern region of the study area contain more than 90% of terrigenous component which appears to be mainly controlled by input of ice-rafted debris.

Stable isotope ratios of foraminifera from the continental shelf off Troms, Northern Norway

A stable oxygen and carbon isotope stratigraphy is established for a Late Weichselian/Holocene glaciomarine/marine seguence in Andfjorden and Malangsdjupet on the continental shelf off Troms, Northern Norway. The stratigraphy demonstrates that the global signals, Termination I B and possibly also I A (upper parts), are present and radiocarbon date to 10.3-9.7 kyr B.P. and >14-13.5 kyr B.P., respectively. A temperature increase of 5°-6°C and possibly a small salinity increase occurred during Term. I. A near-glacial environment between 13 and 14 kyr B.P. was characterized by poorly ventilated bottom waters followed by a meltwater pulse at circa 13 kyr B.P. During the beginning intrusion of Atlantic Water between 13 and 10 kyr B.P., the bottom water was characterized by somewhat fluctuating temperatures and salinities. Temperatures close to those of the present were established around 9.7 kyr B.P. and seem to have been rather stable since.