Search for dissertations about: "Varved annually laminated lake sediment"

Showing result 1 - 5 of 6 swedish dissertations containing the words Varved annually laminated lake sediment.

  2. 1. Varved lake sediments and diagenetic processes

    Author : Veronika Gälman; Ingemar Renberg; Daniel Conley; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Varved annually laminated lake sediment; diagenesis; varve appearance; iron; sulfur; chemical speciation; iron cycling; carbon; nitrogen; stabile isotopes; δ13C; δ15N; Earth sciences; Geovetenskap;

    Abstract : Varved (annually laminated) sediments are of great interest for inference of past environmental conditions, as they provide dated records with high time resolution. After deposition, the sediment varves are affected by diagenesis; i.e., chemical, physical and biological changes that occur within the sediment. READ MORE

  4. 2. Combining limnology and paleolimnology : a refined understanding of environmental sediment signal formation in a varved lake

    Author : Dominique Béatrice Maier; Christian Bigler; Sebastian Diehl; Jasmine E. Saros; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; varved lake sediments; diatom sediment signal formation; sequential sediment trap; seasonal process timing; ice thinning; varve compaction; climate impact; catchment properties; Earth Sciences with Specialization Environmental Analysis; geovetenskap med inriktning mot miljöanalys;

    Abstract : Paleoclimatic archives, such as lake sediments, extend our understanding of terrestrial and aquatic ecosystem dynamics in relation to climate variability beyond the period covered by instrumental data. In this context, annually laminated (i.e. READ MORE

  5. 3. Setting the Holocene clock using varved lake sediments in Sweden

    Author : Lovisa Zillén; Kvartärgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; climate change; Physical geography; tephrochronology; palaeomagnetic secular variations; radiocarbon time-scale; Holocene varved lake sediments; varve chronology; geomorphology; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

    Abstract : The aim of this thesis was to study annually laminated (varved) Holocene lake sediment in Sweden, their formation and their potential as chronological and palaeoecological archives. Five lakes with continuous Holocene varved lake sediment sequences in northern (Västerbotten) and west central Sweden (Värmland) were investigated. READ MORE

  6. 4. Studies of an elusive element : processes that influence the net retention of mercury in lake sediments and peatlands

    Author : Johan Rydberg; Richard Bindler; Carl Lamborg; Umeå universitet; []
    Keywords : Mercury; retention; lake sediments; peatlands; environmental archives; sedimentation; diagenesis; vegetation; permafrost; Environmental Science; miljövetenskap;

    Abstract : Because of its toxic nature mercury is a threat to both wildlife and human health, and thus, it is an element of concern in the environment. Currently much of the mercury emitted to the atmosphere is derived from anthropogenic sources – both direct emissions and re-emission of already deposited anthropogenic mercury. READ MORE

  7. 5. Functional clustering methods and marital fertility modelling

    Author : Per Arnqvist; Sara Sjöstedt de Luna; Leif Nilsson; Helle Sørensen; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; censoring; Coale-Trussell model; EM-algorithm; functional data analysis; functional clustering; marital fertility; normal approximation; Poisson process; varved lake sediments; warping; Mathematical Statistics; matematisk statistik;

    Abstract : This thesis consists of two parts.The first part considers further development of a model used for marital fertility, the Coale-Trussell's fertility model, which is based on age-specific fertility rates. A new model is suggested using individual fertility data and a waiting time after pregnancies. READ MORE