Sökning: "Britta Sannel"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Britta Sannel.

  1. 1. Holocene dynamics in subarctic peat plateaus of west-central Canada : Vegetation succession, peat accumulation and permafrost history

    Författare :A. Britta K. Sannel; Peter Kuhry; Peter Jansson; Ian Brown; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; peatlands; permafrost; carbon accumulation; fire; subarctic; Holocene; Physical geography; Naturgeografi;

    Sammanfattning : Dynamics in vegetation, permafrost and peat and net carbon accumulation rates throughout the Holocene have been studied in two subarctic peat plateaus of west-central Canada through plant macrofossil analysis, geochemical analyses and AMS radiocarbon dating. Peatland formation at the studied sites began around 6600-5900 cal yr BP as a result of paludification of upland forests. LÄS MER

  3. 2. Temporal and spatial dynamics in subarctic peat plateaus and thermokarst lakes

    Författare :A. Britta K. Sannel; Peter Kuhry; Peter Jansson; Ian A. Brown; Serge Payette; Stockholms universitet; []
    Nyckelord :Peatlands; permafrost; subarctic; peat plateau; thermokarst lake; macrofossil analysis; carbon nitrogen ratio; peat accumulation; carbon accumulation; remote sensing; binary encoding; time-series analysis; Physical Geography; naturgeografi;

    Sammanfattning : Permafrost peatlands are widespread at high northern latitudes and are important soil organic carbon reservoirs. A future warming in these areas, as suggested by global climate models, can cause thawing and increased ground subsidence (thermokarst), resulting in changes in surface hydrology and ecosystem functioning. LÄS MER

  4. 3. Ashes to ashes : Applications of tephrochronology in Scandinavia

    Författare :Simon A. Larsson; Stefan Wastegård; Britta Sannel; Christine Lane; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; tephrochronology; tephrostratigraphy; tephra; palaeoclimate; Last Glacial–Interglacial Transition; Scandinavia; naturgeografi; Physical Geography;

    Sammanfattning : The project presented in this thesis provides two examples of applications of tephrochronology in Scandinavia. The usage of tephra deposits preserved in sediments—i.e. LÄS MER

  5. 4. Tephra horizons in the North Atlantic region during the Early Holocene

    Författare :Ewa Lind; Stefan Wastegård; Margareta Hansson; Britta Sannel; Victoria Smith; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tephrochronology; geochemical composition; Saksunarvatn Ash; Vedde Ash; Fosen Tephra; Askja-S; palaeoclimate; Younger Dryas; Early Holocene; “XRF ITRAX”; sediment geochemistry; stable isotopes; Faroe Islands; Norway; Sweden; kvartärgeologi; Quaternary Geology;

    Sammanfattning : Uncertainties about the rate and magnitude of future climate change have drawn attention to the climate variability following the Late Glacial-Early Holocene transition, c. 12-8 ka BP. LÄS MER

  7. 5. 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