Search for dissertations about: "Quaternary environmental changes"

Showing result 1 - 5 of 42 swedish dissertations containing the words Quaternary environmental changes.

  2. 1. Arctic Ocean benthic foraminifera preservation and Mg/Ca ratios : Implications for bottom water palaeothermometry

    Author : Natalia Barrientos; Helen Coxall; Martin Jakobsson; Steve Barker; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arctic Ocean; benthic foraminifera; Mg Ca-temperature; calcite preservation; Marine Geology; maringeologi;

    Abstract : Reconstructions of Arctic Ocean palaeotemperatures are needed to disentangle natural variability from anthropogenic changes and understand the role of ocean heat transport in forcing or providing feedbacks on Arctic climate change. Despite known complications with calcareous microfossil preservation in Arctic Ocean sediments, calcareous benthic foraminifera can be common in interglacial sequences. READ MORE

  4. 2. Late Quaternary Biostratigraphy and Paleoceanography of the central Arctic Ocean

    Author : Daniela Hanslik; Martin Jakobsson; Marit-Solveig Seidenkrantz; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Arctic Ocean; Quaternary; biostratigraphy; foraminifera; paleoceanography; Other earth sciences; Övrig geovetenskap; Marine Geoscience; marin geovetenskap;

    Abstract : The central Arctic Ocean is one of the least explored deep sea regions and long biostratigraphic sediment records are sparse. The main focus of this thesis is the Arctic Ocean foraminiferal record and its application to reconstruct paleoceanographic variations and summer sea ice cover changes between late Quaternary interglacial periods. READ MORE

  5. 3. Environmental history in southern Mozambique : Reconstruction of flooding events, hydroclimate and sea-level dynamics since mid-Holocene

    Author : Sandra Raúl Sitoe; Jan Risberg; Elin Norström; Lars-Ove Westerberg; John Compton; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Southern Africa; Limpopo River floodplain; flooding event; sea-level change; climate change; diatoms; phytoliths; mineral magnetics; grain-size; radiocarbon dating; kvartärgeologi; Quaternary Geology;

    Abstract : The aim of this thesis has been to reconstruct paleoenvironment, paleohydrology and paleoclimate in coastal southern Mozambique, with emphasis on tracing past flooding events on the lower Limpopo River floodplain. In order to extend flood chronologies beyond periods covered by instrumental data, sediments from lakes on the floodplain were studied (Lake Lungué, Coassane Oxbow, Lake Magandane and Lake Soane). READ MORE

  6. 4. Past environmental and climate changes in northern Tanzania : Vegetation and lake level variability in Empakaai Crater

    Author : Maria Ryner; Karin Holmgren; Peter Kuhry; Lars-Ove Westerberg; Henry Lamb; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; palaeoecology; palaeolimnology; physical and societal factors; Holocene; Tanzania; Lake Emakat; Engaruka; Earth sciences; Geovetenskap; Physical Geography; geografi med naturgeografisk inriktning;

    Abstract : This thesis presents palaeoenvironmental data from equatorial Africa covering two important time intervals; i) the warming period forming the Pleistocene/Holocene transition and ii) the last millennium. The Empakaai Crater, in northern Tanzania contains a lake from where sediment cores, spanning two time-slices 14.8-9. READ MORE

  7. 5. Benthic environmental responses to climatic changes during the late Quaternary: a micropalaeontological and geochemical approach

    Author : Claire McKay; Kvartärgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; late Quaternary; rapid climate change; Benguela; Mauritania; productivity; upwelling; benthic foraminifera;

    Abstract : 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. READ MORE