Essays about: "diatom proxy"

Found 5 essays containing the words diatom proxy.

  1. 1. Mercury accumulation in lake sediments on different time scales – the influence of algal primary production

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

    Author : Anne Rebotzke; [2023]
    Keywords : mercury; lake sediment; primary productivity; algal scavenging; biogenic silica; diatom proxy; chlorophyll-a; organic matter;

    Abstract : The aim of this work is to test the proposed approach of algal scavenging as a driver of sediment mercury (Hg) on different time scales and to gain a better understanding of the mechanisms of Hg accumulation in lake sediments. A 3000-year sediment record from Nylandssjön in northern Sweden was analysed for this purpose, as well as a 20-year sediment record from the seasonal sediment traps of this lake. READ MORE

  3. 2. Diatoms from the late Holocene of the western Chukchi Sea, Arctic Ocean: environmental signals and palaeoceanography

    University essay from Stockholms universitet/Institutionen för geologiska vetenskaper

    Author : Erik Browaldh; [2022]
    Keywords : diatoms; late holocene; SWERUS-L2-2-PC1; Herald Canyon; Chukchi Sea; ice-algae; sympagic; cryophilic; warm water diatom; Bering Sea Water species; bottom water temperature; BWT; benthic foraminifera; palaeothermometry; ice dynamics; Fragilariopsis; Fossula arctica; Paralia sulcata; Shionodiscus oestrupii; Thalassiosira simonsenii; Chaetoceros; Chaetoceros sp. 7;

    Abstract : The sediment Core SWERUS-L2-2-PC1 (2PC) retrieved from the Chukchi Sea, Arctic Ocean sits in an oceanographically dynamic location at the Arctic-Pacific Ocean gateway. The 8.3 m-long core was retrieved in Herald Canyon at the marginal ice zone at 57 m depth. READ MORE

  4. 3. Paleogeography and shore displacement of Eastern Gotland between 9.5 and 2.8 ka cal BP

    University essay from Stockholms universitet/Institutionen för naturgeografi

    Author : Aleftin Barliaev; [2017]
    Keywords : ;

    Abstract : Located in the middle part of the Baltic, the island of Gotland underwent major environmental changes, associated with different stages of the development of the basin during the Holocene, and therefore represents a promising location for shore-displacement studies. This thesis is focused on a palaeohydrological evolution of the Lina Mire, central eastern part of Gotland, in the Middle Holocene and aims to reconstruct the timing and environment of the Littorina transgression. READ MORE

  5. 4. The effects of population growth on Ecosystem services in lake Ekoln : A multi-proxy data analysis of a lake core and historical records.

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

    Author : Douglas Kilpatrick; [2016]
    Keywords : Ecosystem services; Population growth; Species diversity; Water quality; Environmental reconstruction.;

    Abstract : Throughout human history man has utilized the environment to varying degrees, depending on technology and population. These ¨ecosystem services¨ have suffered sustained degradation over the centuries, resulting in large investments having to be made to prevent and reverse further changes to the environment. READ MORE

  6. 5. A multi-proxy study of a Holocene peat sequence on Nightingale Island, South Atlantic

    University essay from Lunds universitet/Geologiska institutionen

    Author : Hanna Lindvall; [2011]
    Keywords : Nightingale Island; South Atlantic; Holocene; peat; C N; environmental reconstruction; interglacial bipolar see-saw; Sydatlanten; Holocen; torv; miljörekonstruktion; interglacial gungbrädeseffekt; Earth and Environmental Sciences;

    Abstract : Nightingale Island is situated at 37°S in the central part of the South Atlantic Ocean, which is a sensitive location for variations within the Atlantic Meridional Overturning Circulation (AMOC) and the Southern Hemisphere Westerlies (SHW) wind belt. A peat sequence from the wetland 2nd Pond has been investigated with emphasis on the composition of the deposits, loss on ignition (LOI), total Carbon (TC), Nitrogen (N), biogenic Silica (BSi), magnetic susceptibility (MS), diatom counting and macrofossil analysis. READ MORE