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Visar resultat 1 - 5 av 6 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Holocene climate and environmental dynamics on the Tristan da Cunha island group, South Atlantic

   Författare :Karl Ljung; Kvartärgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; palynologi; Geology; climate change; pollen analysis; Palaeobotany; phylogeny; palynology; Paleobotanik; fylogeni; vegetation change; gyttja; peat; Holocene; Quaternary; South Atlantic; Tristan da Cunha; physical geography; Geologi; fysisk geografi;

   Sammanfattning : It has been shown that the present interglacial has been climatically dynamic with both rapid and severe climatic fluctuations. The spatial and temporal differences of these changes are however not fully resolved. The aim of this thesis is to present a detail high resolution record of past climate changes from the central South Atlantic. LÄS MER

3. 2. A song of ice and mud : Interactions of microbes with roots, fauna and carbon in warming permafrost-affected soils

   Författare :Sylvain Monteux; Ellen Dorrepaal; Frida Keuper; James T. Weedon; Joshua Schimel; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; microbial communities; permafrost; functional limitations; rhizosphere; SOM decomposition; soil fauna; climate change; carbon dioxide;

   Sammanfattning : Permafrost-affected soils store a large quantity of soil organic matter (SOM) – ca. half of worldwide soil carbon – and currently undergo rapid and severe warming due to climate change. LÄS MER

4. 3. Post-Glacial History of Sea-Level and Environmental Change in the Southern Baltic Sea

   Författare :Marloes Kortekaas; Kvartärgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kartografi; klimatologi; Geofysik; fysisk oceanografi; physical oceanography; meteorology; Sedimentologi; Stratigrafi; Stratigraphy; Baltic Sea; geokemi; Petrologi; mineralogi; geochemistry; mineralogy; Petrology; greigite; mineral magnetics; sea-level changes; Holocene; Littorina transgression; geomorphology; pedology; cartography; climatology; meteorologi; Geophysics; Sedimentology; Optically Stimulated Luminescence OSL ; Fysisk geografi; geomorfologi; marklära; Physical geography;

   Sammanfattning : A new palaeoenvironmental record of the post-glacial history of the southern Baltic Sea (~14 ka to present) is presented. During this period, large water level and salinity changes occurred in the Baltic Basin due to opening and closing of connections to the North Atlantic. LÄS MER

5. 4. Design and implementation of a programmable, wideband sonar for sediment mapping

   Författare :Peter Jonsson; Teknisk geologi; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; centroid; programmable sonar; sediment mapping; underwater acoustics; hydroacoustics; echosounder;

   Sammanfattning : To be able to explore different signal types and processing techniques, apt for sediment mapping, programmable, fully digital profiling systems has been built and tested. The systema are designed to be deployed also at small water depths from small boats, without special handling equipment. LÄS MER

7. 5. Environmental applications of biogeochemical data from Geological Survey of Sweden

   Författare :Kaj Lax; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

   Sammanfattning : The Geological Survey of Sweden, SGU, has carried out geochemical mapping for several decades. In 1983, two regional mapping programmes were initiated, aiming at a nation wide coverage. LÄS MER