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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

A Regional Analysis of Changing Climate Conditions and Glacier Mass Balance in Svalbard / En regional analys av förändrade klimatförhållanden och den glaciala massbalansen på Svalbard

Bergman, Ottar January 2019 (has links)
The Arctic archipelago of Svalbard has experienced among the greatest increases in temperature on Earth in the last few decades. The changing climatic conditions have a large impact on the glacier mass balance. This study makes use of a highresolution model dataset with data on climatic and glacier conditions on Svalbard from 1957 to 2018. The model dataset is used to analyse the spatiotemporal variability in glacier mass balance across Svalbard and linking those changes to long-term trends in meteorological conditions. The study is focused on the spatial gradients in trends between two regions in Svalbard, the coldest part of the archipelago, Nordaustlandet and the milder southern part of the main island Spitsbergen. The north eastern (NE) region is found to have a greater increase in annual air temperature over the simulation period with 5.5 °C compared to 3.5 °C for the south western (SW) region. The increase in annual summer temperatures is much smaller with a total increase of 1 °C for the NW and 1.5 °C for the SW. Both regions show a small, but significant, increase of precipitation. Relative humidity and cloud cover in the NE are increasing slightly over the time period, probably due to retreating sea ice cover. Glacier melt and runoff are increasing in both regions, which is contributing to significant negative trends in the mass balance. The increase in melt and run off is stronger in the SW than in the NE. There’s a strong correlation between summer air temperature and glacier mass balance, melt and runoff. Refreezing in the NE is decreasing much faster than in the SW. Refreezing is strongly correlated with annual air temperatures in the NE and not in the SW, probably due to lower temperatures in the NE region.
32

Tažní psi v Arktidě jako potenciální zdroj parazitárních infekcí lidí a volně žijících zvířat

BROŽ, Marek January 2018 (has links)
The aim of this thesis is to evaluate dogs introduced into the Arctic as a source of intestinal parasites infection both for wildlife and humans. To that aim coprological examination of faeces sampled in Svalbard and Greenland was performed. Microscopical and molecular detection of cryptosporidia, giardiae, microsporidia, roundworms and tapeworms in faeces was carried out. One sample from Svalbard was positive for Toxocara canis eggs and four samples from Svalbard were positive for unusual genotype of Enterocytozoon bieneusi.
33

The development and relative chronology of landforms at Kongsfjordhallet, Spitsbergen

Peterson, Gustaf January 2008 (has links)
<p>Kongsfjordhallet is situated at 79° N on the North coast of Kongsfjorden, Spitsbergen.The landscape shows a large diversity of landforms and sediments and the aim of thisstudy has been to investigate the spatial distribution and temporal differences betweenthese landforms.The most prominent landform is interpreted as a lateral moraine dividing the area fromsoutheast to northwest. This is probably a sign of a standstill during the deglaciation ofan ice-sheet glacier tongue filling the fjord. The valley-glaciers at Kongsfjordhallet haveadvanced after this event and left end moraines on top of the lateral moraine. Largeamounts of meltwater have eroded parts of the Kongsfjordhallet, creating several fossilmeltwater channels that dissect the landscape. Erratic boulders of mainly gneiss type arescattered all over the landscape, as high up as 500 m a.s.l. In addition to the erraticboulders, a lot of allochthonous material is found incorporated in local material,especially as a diamict interpreted as till that covers large parts of Kongsfjordhallet.The till can likely be correlated to one of the diamict units in the cliff sections at theKongsfjordhallet coast. At present, two large ravines drain the area, moving water fromthe glaciers to the ocean and a beach is developing in the Southeast part of the area dueto ocean transgression. Landforms from two glacial events are found, one regional andone local. An episode of high sea-level as well as fluvial and mass-wasting activity afterthe deglaciation is also recorded. The formation of the landforms in the area is believedto be after the Last Glacial Maximum and into the Holocene, but no absolute dates areavailable.</p> / SciencePub
34

The tectonic evolution of northwest Svalbard

Pettersson, Carl Henrik January 2010 (has links)
Svalbard represents the uplifted and exhumed northwest corner of the Barents Sea Shelf. Pre-Carboniferous rocks of Svalbard are divided into the Eastern, Northwestern and Southwestern Terranes, were amalgamated during the Caledonian Orogen and are separated by north-south-trending strike-slip faults. Even though our knowledge of Svalbard’s pre-Carboniferous history has increased dramatically during the last two decades, a major issue remains: Where did the different tectonostratigraphic terranes of Svalbard originate? The answer to this question has profound significance for the entire eastern Laurentian margin, which spans two supercontinent cycles, from the amalgamation and breakup of Rodinia to the amalgamation of Pangea. This thesis constrains the tectonothermal evolution of Svalbard’s Northwestern Terrane (NWT) using ion microprobe and LA-ICP-MS U-Pb zircon geochronology and electron microprobe thermobarometry on metasediments, clastic rocks and granitoids. Detrital zircon age populations of metasediments from the NWT suggests that they (e.g. the Krossfjorden Group) were deposited at c. 1000 Ma in a remnant ocean basin setting outboard the Eastern Grenville Province and were subsequently deformed and intruded by Late Grenvillian granitoids during the final suturing of Rodinia. Thus, a northern branch of the Grenvillian/Sveconorwegian orogeny is not present. This older history of the NWT is extensively overprinted by Late Caledonian deformation and metamorphism, with peak metamorphic conditions of 850 °C at &gt;6 kbars, and subsequent migmatization of the Krossfjorden Group at c. 420 Ma. Based on these data, together with the detrital zircon age population from overlying Late Silurian-Early Devonian clastic rocks, a unifying model is proposed involving fragments from the Grampian orogen and Avalonian crust originally accreted to the Laurentian margin, subsequently transported northwards along sinistral strike-slip faults during Scandian deformation. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 4: In press.
35

Separating Acetate, Formate and MSA from natural samples using ion chromatography / Separera Acetat, Format och MSA från naturliga prover med jonkromatografi

Drake, Alexandra January 2013 (has links)
Anjoner från de tre korta organiska syrorna: acetat, format och MSA är intressanta att mäta då de kan användas för olika sorters miljöstudier. Jonkromatografen vid Institutionen för Geovetenskaper kan för närvarande inte skilja på dessa tre ämnen, därför utvecklades sex nya metoder i detta projekt för att lösa problemet. Metod 5 visade sig vara den bästa, där acetat och format separerades. Resultatet ansågs vara bra, även om MSA inte separerades. Metod 5 testades sedan på ett par naturliga prover; vatten-, snö- och isprover. Alla dessa prover visade en större mängd av format än acetat, som i vissa fall inte ens visades. Resultaten verkade rimliga, inte många av dem stack ut i jämförelse till andra resultat av samma fas. Det ytligaste provet från Lomonosovfonnaglaciären skiljer sig dock ganska mycket i mängden format jämfört med prover från andra djup av denna iskärna, förmodligen på grund av kontamination vid hanteringen av proverna både vid provtagningen och i labbet. MSA kan dock även mätas om man vet mängden acetat och format i provet. Detta görs genom tillsats av kända mängder av MSA till samma prov i efterföljande körningar, för att sedan kunna beräkna koncentrationen av MSA i provet. Problemet med denna metod är att koncentrationen av MSA måste vara tillräckligt hög i kontrast till koncentrationerna av acetat och format för att få tillförlitliga resultat, vilket den inte var i det här projektets analyserade prover. / Anions from three short organic acids: acetate, formate and MSA are interesting to measure since they can be used for different environmental studies. The ion-chromatographer at the Department of Earth Sciences is currently not able to separate these three substances; therefore six new methods were developed in this project to solve this problem. Short organic test 5 ended up to be the best method, where acetate and formate were separated. The result was considered good, even if MSA were not separated. Method 5 was then tested on a couple of natural water, snow and ice samples. All these samples showed a larger amount of formate than of acetate, which in some cases was not even found. The results seemed plausible; not many of them were sticking out compared to others of the same phase. The shallowest sample from the Lomonosovfonna ice cap did however differ quite a lot in amount of formate compared with samples from other depths of this ice core; probably because of contamination which could have occurred at both the ice cap and in the lab during the handling of the samples. MSA can however also be measured if the amount of acetate and formate in the sample is known. This is done by adding known amounts of MSA to the same sample in subsequent runs to then be able to calculate the concentration of MSA in the sample. The problem with the use of this method is that the concentration of MSA needs to be high enough in contrast to acetate and formate in order to get reliable results, which was not the case in the samples measured in this project.
36

The Northward Course of the Anthropocene : Transformation, Temporality and Telecoupling in a Time of Environmental Crisis

Paglia, Eric January 2016 (has links)
The Arctic—warming at twice the rate of the rest of the planet—is a source of striking imagery of amplified environmental change in our time, and has come to serve as a spatial setting for climate crisis discourse. The recent alterations in the Arctic environment have also been perceived by some observers as an opportunity to expand economic exploitation. Heightened geopolitical interest in the region and its resources, contradicted by calls for the protection of fragile Far North ecosystems, has rendered the Arctic an arena for negotiating human interactions with nature, and for reflecting upon the planetary risks and possibilities associated with the advent and expansion of the Anthropocene—the proposed new epoch in Earth history in which humankind is said to have gained geological agency and become the dominant force over the Earth system. With the Arctic serving as a nexus of crosscutting analytical themes spanning contemporary history (the late twentieth and the early twenty-first century until 2015), this dissertation examines defining characteristics of the Anthropocene and how the concept, which emerged from the Earth system science community, impacts ideas and assumptions in historiography, social sciences and the environmental humanities, including the fields of environmental history, crisis management and security studies, political geography, and science and technology studies (STS). The primary areas of empirical analysis and theoretical investigation encompass constructivist perspectives and temporal conceptions of environmental and climate crisis; the role of science and expertise in performing politics and shaping social discourse; the geopolitical significance of telecoupling—a concept that reflects the interconnectedness of the Anthropocene and supports stakeholder claims across wide spatial scales; and implications of the recent transformation in humankind’s long duration relationship with the natural world. Several dissertation themes were observed in practice at the international science community of Ny-Ålesund on Svalbard, where global change is made visible through a concentration of scientific activity. Ny-Ålesund is furthermore a place of geopolitics, where extra-regional states attempt to enhance their legitimacy as Arctic stakeholders through the performance of scientific research undertakings, participation in governance institutions, and by establishing a physical presence in the Far North. This dissertation concludes that this small and remote community represents an Anthropocene node of global environmental change, Earth system science, emergent global governance, geopolitics, and stakeholder construction in an increasingly telecoupled world. / <p>QC 20151211</p>
37

Geografický průvodce arktickým územím - Špicberky / Geographical guide of the arctic area - Špicberky

VYHLÍDKA, Robert January 2014 (has links)
The main aim of this thesis is a preparation of the first Czech geographical guide to the arctic area of Spitsbergen (Svalbard). The thesis is based on English and German specialized books as well as on author´s personal experience that he gained during his three months working stay in there. Theoretical part consists of minute description in accordance with practice used for generation of geographical guidebooks. In practical part of the thesis is author´s draft of his own routes tracing, including thein difficulty, photos and specification. Part of it will work sheets for secondary school pupils, presentation and methodical manual for teachers.
38

The development and relative chronology of landforms at Kongsfjordhallet, Spitsbergen

Peterson, Gustaf January 2008 (has links)
Kongsfjordhallet is situated at 79° N on the North coast of Kongsfjorden, Spitsbergen.The landscape shows a large diversity of landforms and sediments and the aim of thisstudy has been to investigate the spatial distribution and temporal differences betweenthese landforms.The most prominent landform is interpreted as a lateral moraine dividing the area fromsoutheast to northwest. This is probably a sign of a standstill during the deglaciation ofan ice-sheet glacier tongue filling the fjord. The valley-glaciers at Kongsfjordhallet haveadvanced after this event and left end moraines on top of the lateral moraine. Largeamounts of meltwater have eroded parts of the Kongsfjordhallet, creating several fossilmeltwater channels that dissect the landscape. Erratic boulders of mainly gneiss type arescattered all over the landscape, as high up as 500 m a.s.l. In addition to the erraticboulders, a lot of allochthonous material is found incorporated in local material,especially as a diamict interpreted as till that covers large parts of Kongsfjordhallet.The till can likely be correlated to one of the diamict units in the cliff sections at theKongsfjordhallet coast. At present, two large ravines drain the area, moving water fromthe glaciers to the ocean and a beach is developing in the Southeast part of the area dueto ocean transgression. Landforms from two glacial events are found, one regional andone local. An episode of high sea-level as well as fluvial and mass-wasting activity afterthe deglaciation is also recorded. The formation of the landforms in the area is believedto be after the Last Glacial Maximum and into the Holocene, but no absolute dates areavailable. / SciencePub
39

Eternal sunshine on the flower-spotted ground : Investigating diel rhythms during midnight sun on high-Arctic pollinators

Djurberg, Emma Limosa January 2021 (has links)
With over 600 articles about terrestrial invertebrates in Svalbard we still lack basic knowledge about pollinator-plant interactions in this part of the high-Arctic. It has never before been investigated how the activity of pollinators varies over a 24-hour timeframe in the high Arctic. Insects in the lower Arctic have been shown to have their peak foraging around noon but as Svalbard experiences midnight sun during the whole summer season pollinators could potentially forage any time during the 24-hour day. In this study pictures were taken every minute over cushions of Silene acaulis, capturing visiting pollinators during 5 days around the beginning of July 2019. Pollinators showed no higher abundance around noon. Instead, no significant difference in the abundance of pollinators was found between the hours of the 24-hour timeframe. No significant connection between the abundance of insects and temperature was found as well as no significant connection between the abundance of insects and wind. The results in this study can contribute to fill the knowledge gap of pollinator-plant interactions in Svalbard and show the need for more research about pollinators temporal dynamics in the high-Arctic.
40

PERMAFROST ARCHITECTURE: EXPLORING RAISED STRUCTURES TO DEVELOP A DESIGN METHOD FOR BUILDING AN ARTS CENTRE ON SVALBARD

Andreev, Anton January 2022 (has links)
No description available.

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