Sökning: "Quaternary geology"

Visar resultat 6 - 10 av 85 avhandlingar innehållade orden Quaternary geology.

1. 6. Late Holocene humidity variability in central Sweden

   Författare :Sofia Andersson; Stefan Wastegård; Gunhild Rosqvist; Kristian Schoning; Frank Chambers; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; humidity change; stable isotopes; Chara spp; Pisidium spp; testate amoebae assemblages; humification; C N ratio; late Holocene; central Sweden; Quaternary geology; Kvartärgeologi; kvartärgeologi; Quarternary Geology;

   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. 7. Terrestrial response to Dansgaard-Oeschger cycles and Heinrich events : the lacustrine record of Les Echets, south-eastern France

   Författare :Daniel S. Veres; Barbara Wohlfarth; John J. Lowe; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lake sediments; palaeoclimate; organic matter; Dansgaard-Oeschger cycles; Heinrich events; MIS 3; Western Europe; Quaternary geology; Kvartärgeologi; Quarternary Geology; kvartärgeologi;

   Sammanfattning : Marine Isotope Stage (MIS) 3 was an interval characterized by large and abrupt temperature changes on a millennial time scale, the so-called Dansgaard-Oeschger (DO) cycles and Heinrich events. Evidence for this high-frequency climate variability has been identified in many marine and ice core records. LÄS MER

4. 8. Holocene climate change in high latitudes recorded by stable isotopes in peat

   Författare :Päivi Kaislahti Tillman; Steffen Holzkämper; Stefan Wastegård; Peter Kuhry; Mats Rundgren; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; -; Quaternary geology; Kvartärgeologi; kvartärgeologi; Quarternary Geology;

   Sammanfattning : A key to the understanding of natural and human induced climate variations is to reconstruct past changes from different environments. No outstanding method for general use has been pinpointed, instead, a need of multi-proxy studies is often stressed and the reconstructions are under constant improvement by new techniques. LÄS MER

5. 9. The sensitivity of Swedish alpine lakes to hydro-climatic changes during the Late Holocene

   Författare :Annika Berntsson; Gunhild Rosqvist; Peter G. Langdon; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; alpine lake sediments; temperature reconstruction; precipitation; catchment erosion; chironomids; oxygen isotopes; XRF core scanning; geomorphology; grain size analysis; kvartärgeologi; Quaternary Geology;

   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

7. 10. 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