Sökning: "Tephrochronology"

Visar resultat 6 - 10 av 10 avhandlingar innehållade ordet Tephrochronology.

  1. 6. Towards a Holocene tephrochronology for the Azores

    Författare :Hans Johansson; Stefan Wastegård; Otto Hermelin; Ewa M. Lind; Christine S. Lane; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kvartärgeologi; Quaternary Geology;

    Sammanfattning : The Azores is situated in the North Atlantic Ocean and is one of the most active volcanicregions in the Northern Hemisphere. The volcanic history of the islands is fairly wellknown and several explosive trachytic eruptions have been reported but the geochemicalcompositions of the glass component of the tephra as well as the dispersal oftephras to distal areas are less well known. LÄS MER

  3. 7. Towards an Early Holocene Tephrochronology for the Faroe Islands: Methodology and first results

    Författare :Ewa Lind; Stefan Wastegård; Margareta Hansson; Britta Sannel; Jane Boygle; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quarternary Geology; kvartärgeologi;

    Sammanfattning : The uncertainties regarding future climate change have put considerable notice to the climate variability following the Late Glacial-Holocene transition (ca. 13-9 ka BP) in the North Atlantic region as well as the forcing mechanisms behind climate changes. LÄS MER

  4. 8. Lake sediments around the Antarctic Peninsula : archives of climatic and environmental changes

    Författare :Rolf Zale; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lake sediments; Antarctic Peninsula; radiocarbon dating; climatic and environmental changes; sediment chemistry; naturgeografi; Physical Geography;

    Sammanfattning : Lakes and lake sediments from four areas around the Antarctic Peninsula are described.The concentrations of trace metals in sediment are found to be a useful tool in distinguishing between the different sedimentary phases during a transition from marine to limnic environment. LÄS MER

  5. 9. Tephrochronological Studies in Scotland and Sweden

    Författare :Carl Lilja; Stefan Wastegård; Ian Matthews; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geology; geologi;

    Sammanfattning : The study of palaeoclimates, especially the rapid climate changes during the Last Glacial-Interglacial Transition (LGIT ca. 15-8 ka BP), requires precise dating as well as the ability to link climate records over large regional areas. LÄS MER

  7. 10. The colour of climate : A study of raised bogs in south-central Sweden

    Författare :Anders Borgmark; Stefan Wastegård; Ann-Marie Robertsson; Bas van Geel; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Holocene; south-central Sweden; peat humification; bog hydrology; climate variation; spectral analysis; Quaternary geology; Kvartärgeologi;

    Sammanfattning : This thesis focuses on responses in raised bogs to changes in the effective humidity during the Holocene. Raised bogs are terrestrial deposits that can provide contiguous records of past climate changes. Information on and knowledge about past changes in climate is crucial for our understanding of natural climate variability. LÄS MER