Essays about: "tephra"

Showing result 1 - 5 of 8 essays containing the word tephra.

  1. 1. Towards a Tephrochronology for the Lakselv Peat Sequence in Finnmark County, Northern Norway

    University essay from Stockholms universitet/Institutionen för naturgeografi

    Author : Anny Höglund; [2017]
    Keywords : Tephra; Tephrochronology; Lakselv; Norway; Jan Mayen; São Miguel; Electron Microprobe Analysis; Density Separation;

    Abstract : To provide an increased breadth in the knowledge of tephra dispersal, this pilot study examines a peat core from Lakselv in Finnmark County in northern Norway. Peat samples are exposed to burning, HCl, density separation and polarized light microscopy. One sample from a depth of 37.5-40 cm was analysed using an electron microprobe analyser (EMPA). READ MORE

  2. 2. The late Holoce 14C reservoir age in the Chukchi Sea as inferred from tephra in marine sediments

    University essay from Stockholms universitet/Institutionen för geologiska vetenskaper

    Author : Aron Varhelyi; [2016]
    Keywords : Tephra; Aniakchak; Holocene; Chukchi Sea;

    Abstract : Volcanic ash, or tephra, blankets the local and regional landscape following a volcanic eruption. If this ash layer is preserved and identified, it can act as a time synchronous marker bed (isochron) for correlation between marine, terrestrial, glacial and lacustrine deposits. READ MORE

  3. 3. Environmental and Climate ChangeDuring Holocenein Hjaltadalur,Skagafjördur, North Iceland : -Peat core analysis and pollenidentification

    University essay from Uppsala universitet/Institutionen för geovetenskaper

    Author : Jenny N. Johansson; [2013]
    Keywords : Climate change; Holocene; Pollen; Peat; Iceland; Hjaltadalur; human impact; Landnám;

    Abstract : Northern Iceland is a place of great interest for climatic studies. The land was fairly untouched by human activity until the Landnám period (870-930 AD), when humans first started to colonize the island. READ MORE

  4. 4. Recent Icelandic Tephra in a Swedish Peat Deposit

    University essay from Stockholms universitet/Institutionen för naturgeografi och kvartärgeologi (INK)

    Author : Eric Skoglund; [2012]
    Keywords : tephra; ash; eyjafjallajökull; peat deposit; ash spread; ash cloud; aska; tephra; torv; askmoln; eyjafjallajökull;

    Abstract : Two eruptions from Icelandic volcanoes have in the last years caused widespread dispersalof volcanic ash in the atmosphere. The transportation of tephra from Iceland to mainlandEurope is not an uncommon event and it can cause large disruptions to society. READ MORE

  5. 5. Tephrochronology : Methodology and correlations, Antarctic Peninsula Area

    University essay from Umeå universitet/Institutionen för ekologi, miljö och geovetenskap

    Author : Mats Molén; [2012]
    Keywords : Tephrochronology Antarctica Molén Zale Deception Island LA-ICP-MS EDS WDS SEM;

    Abstract : AbstractMethods for tephrochronology are evaluated, in the following way: Lake sediments <500 years old from three small Antarctic lakes were analysed for identification of tephras. Subsamples were analysed for a) grain size, and identification and concentration of volcanogenic grains, b) identification of tephra horizons, c) element abundance by EPMA WDS/EDS and LA-ICP-MS, and d) possible correlations between lakes and volcanoes. READ MORE