Sökning: "datering"
Visar resultat 16 - 20 av 25 avhandlingar innehållade ordet datering.
16. Vissa drag i Badelundaåsens geohydrologi : (Sträckan Mälaren - Sätra brunn)
Sammanfattning : Undersökningen har genomförts som en hydrogeologisk, lokalregional inventering av Badelundaåsen och dess biåsar. Den speciellt inriktade kartering, som utfördes i skalan 1:20 000 omfattade själva åsen jämte dalens begränsning. LÄS MER
17. Advances in Stellar Astrophysics from Laboratory Spectroscopy
Sammanfattning : Investigation of astrophysical plasmas, such as stellar atmospheres, require both knowledge of atomic structure and data. We present laboratory instruments, techniques and tools for acquisition of the data required to derive important atomic parameters such as, wavelengths, oscillator strengths and line profiles. LÄS MER
18. 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
19. Investigations of temporal changes in climate and the geomagnetic field via high-resolution radiocarbon dating
Sammanfattning : Geological archives have shown periods of abrupt climate change in the relatively stable Holocene epoch (last ca. 11 700 years). One of these periods was around 2800 cal BP. Several records, mainly from Europe, reveal a shift towards wetter, cooler and windier conditions. LÄS MER
20. The palaeolimnological record of regime shifts in lakes in response to climate change
Sammanfattning : Regime shifts in lake ecosystems can occur in response to both abrupt and continuous climate change, and the imprints they leave in palaeolimnological records allow us to investigate and better understand patterns and processes governing ecological changes on geological time scales. This thesis aims at investigating palaeolimnological records of regime shifts in lakes during the Holocene to explore how lake ecosystems responded to climate changes and anthropogenic activities and to identify thresholds or tipping points that produced regime shifts. LÄS MER