Sökning: "Gunhild Rosqvist"
Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Gunhild Rosqvist.
1. Late quaternary equatorial glacier fluctuations
Sammanfattning : On several occasions during the Quaternary, climate permitted equatorial glaciers to advance significantly. In East Africa, where the highest mountains of the African continent are located, evidence of three pre-Weichselian glaciations on Kilimanjaro, and two on Mount Kenya and Ruwenzori were recognized. LÄS MER
2. Late Holocene humidity variability in central Sweden
Sammanfattning : The aim of this thesis was to reconstruct humidity variability in central Sweden during the late Holocene. A multi-proxy approach was used to infer humidity changes as recorded in a lake and a mire. Age-models were constructed based on radiocarbon dating and the Askja-1875 tephra. LÄS MER
3. The sensitivity of Swedish alpine lakes to hydro-climatic changes during the Late Holocene
Sammanfattning : The thesis objective is to use lake sediments to investigate the relationships between chironomids, as proxy for temperature, and δ18O and minerogenic in-wash, as precipitation proxies, in northern Sweden during the Late Holocene. Three lakes along a N–S transect in the Scandes were studied using biological, geochemical and physical sediment properties, together with numerical methods. LÄS MER
4. Waterborne pollution from mining in cold climates : Potential catchment-scale immobilization of substances by microbial sulfate reduction (MSR)
Sammanfattning : Waterborne pollution from mining is impacting groundwater and surface water resources in many regions of the world. Main problems include acidification and high levels of dissolved toxic metals that adversely affect humans and ecosystems. LÄS MER
5. Holocene climate and atmospheric circulation changes in northern Fennoscandia : Interpretations from lacustrine oxygen isotope records
Sammanfattning : This thesis investigates how variations in the oxygen isotopic composition of lake waters in northern Fennoscandia are recorded in lake sediment archives, especially diatoms, and how these variations can be used to infer past changes in climate and atmospheric circulation. Results from analyses of the oxygen isotopic composition of lake water samples (δ18Olakew) collected between 2001 and 2006 show that δ18O of northern Fennoscandian lakes is mainly controlled by the isotopic composition of the precipitation (δ18Op). LÄS MER