Sökning: "YOUNGER DRYAS"
Visar resultat 6 - 10 av 16 avhandlingar innehållade orden YOUNGER DRYAS.
6. Past dynamics of a marine-terminating glacier in lower Borgarfjörður, west Iceland - Analyses of glaciotectonic sediments and landforms
Sammanfattning : Large and complete sections through glacial landforms formed in subaqueous environments are rare, impeding our knowledge of their internal composition and the processes responsible for their formation. Following the last deglaciation of the Icelandic Ice Sheet (IIS), a marine-terminating outlet glacier advanced out of the fjord of Borgarfjörður resulting in large-scale glaciotectonic deformation of glaciomarine sediments. LÄS MER
7. Benthic environmental responses to climatic changes during the late Quaternary: a micropalaeontological and geochemical approach
Sammanfattning : There is a limited understanding of how the benthic environment within upwelling regions responded to past rapid climatic changes. Within this thesis, a multiproxy approach is applied to two marine sediment cores from two coastal upwelling sites in the low latitude subtropical Atlantic. LÄS MER
8. New insights into past atmospheric circulation dynamics
Sammanfattning : Climate change associated with shifts in atmospheric circulation patterns has a great influence on ecosystems and societies. To predict future climate change it is important to obtain a detailed understanding of how climate behaved in the past, with special focus on the regional-scale and short-term expressions of changes in atmospheric circulation dynamics. LÄS MER
9. Late Weichselian and early Holocene changes of vegetation, climate and sea level on the Skagi peninsula, northern Iceland
Sammanfattning : Sediment sequences from five lakes on the Skagi peninsula, northern Iceland, were subjected to mineral magnetic analysis, carbon analysis, pollen analysis, plant macrofossil analysis, diatom analysis, radiocarbon dating and tephra analysis in order to make detailed reconstructions of vegetation, climate and sea level during the Late Weichselian and Early Holocene. The main purpose was to investigate if the dramatic deglacial climatic shifts recorded in proxy records from the North Atlantic region, such as ice cores, marine sediments and lake sediments, also are registered in Skagi lake sediments, which would be expected considering Iceland´s position in the middle of the North Atlantic Ocean, within the range of the Late Weichselian–Early Holocene migrations of the marine polar front. LÄS MER
10. In the wake of deglaciation - sedimentary signatures of ice-sheet decay and sea-level change : Studies from south-central Sweden and the western Arctic Ocean
Sammanfattning : Lacustrine and marine sedimentary archives help unravel details concerning the withdrawal of large ice sheets and resulting sea-level changes during the last deglaciation (22 -11 kyr). In a series of four manuscripts, this PhD thesis investigates the sedimentological signatures from deglacial processes at three key locations in the northern hemisphere: (i) Lake Vättern (LV) in south-central Sweden, (ii) Herald Canyon (HC) in the western Chukchi Sea, and (iii) Mackenzie Trough (MT) on the westernmost edge of the Canadian Beaufort Shelf. LÄS MER