Sökning: "Helena Alexanderson"

Hittade 5 avhandlingar innehållade orden Helena Alexanderson.

1. 1. Glacial geology and palaeo-ice dynamics of two ice-sheet margins, Taymyr Peninsula, Siberia and Jameson Land, East Greenland

   Författare :Helena Alexanderson; Kvartärgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ice dynamics; Pleistocene; Arctic Siberia; East Greenland; Sedimentology; Physical geography; Sedimentologi; pedology; geomorphology; klimatologi; kartografi; marklära; geomorfologi; cartography; Fysisk geografi; ice-marginal processes; glacial history; climatology;

   Sammanfattning : The North Taymyr ice-marginal zone (NTZ) on the Taymyr Peninsula, Arctic Siberia and the Ugleelv Valley on Jameson Land, East Greenland, have been investigated with the aim of reconstructing the glacial history, including depositional processes and environments. Geomorphological, sedimentological, stratigraphical and remote sensing methods have been combined to give a comprehensive view of developments in the two areas. LÄS MER

3. 2. Glacial geology of Bayan Har Shan, northeastern Tibetan Plateau

   Författare :Jakob Heyman; Arjen P Stroeven; Clas Hättestrand; Helena Alexanderson; Mark D Johnson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical geography; Naturgeografi; Physical Geography; naturgeografi;

   Sammanfattning : The paleoglaciology of the Tibetan Plateau is still largely unexplored, despite its importance for regional and global climate reconstructions. In this thesis a comprehensive glacial geological record is presented from an extensive part of the northeastern Tibetan Plateau centred on the Bayan Har Shan. LÄS MER

4. 3. Palaeoglaciology of the northeastern Tibetan Plateau

   Författare :Jakob Heyman; Arjen P Stroeven; Clas Hättestrand; Helena Alexanderson; Frank Lehmkuhl; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Tibetan Plateau; palaeoglaciology; Physical geography; Naturgeografi; Quaternary geology; Kvartärgeologi; Physical Geography; naturgeografi;

   Sammanfattning : This study concerns the palaeoglaciation of the northeastern Tibetan Plateau, with emphasis on the Bayan Har Shan (Shan = Mountain) in the headwaters of Huang He (Yellow River). To reconstruct past glacier development multiple techniques, including remote sensing, field investigations, cosmogenic exposure dating, and numerical modelling have been employed. LÄS MER

5. 4. Late Quaternary ice sheet history and dynamics in central and southern Scandinavia

   Författare :Timothy Johnsen; Helena Alexanderson; James T. Teller; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Scandinavian ice sheet; ice sheet dynamics; luminescence dating; cosmogenic exposure dating; geochronology; moraine; interstadial; deglaciation; nunatak; Quaternary geology; Kvartärgeologi; kvartärgeologi; Quarternary Geology;

   Sammanfattning : Recent work suggests an emerging new paradigm for the Scandinavian ice sheet (SIS); one of a dynamically fluctuating ice sheet. This doctoral research project explicitly examines the history and dynamics of the SIS at four sites within Sweden and Norway, and provides results covering different time periods of glacial history. LÄS MER

7. 5. A multimethod approach to dating Quaternary sediments from the Arctic Ocean

   Författare :Gabriel West; Matthew O'Regan; Darrell Kaufman; Helena Alexanderson; Guillaume St-Onge; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arctic Ocean; Amino Acid Geochronology; Optically Stimulated Luminescence Dating; Palaeomagnetism; maringeologi; Marine Geology;

   Sammanfattning : The marine sedimentary environment in the polar regions is different from the rest of the world’s oceans, as it is greatly influenced by the cryosphere. In the Arctic, sea ice and icebergs can transport vast amounts of sediments, delivered by extensive fluvial systems from the surrounding continents, which have been shaped by the waxing and waning of large terrestrial ice sheets during the Quaternary period. LÄS MER