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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.
11

Strukturální násilí a velmocenské soupeření: Důsledky čínsko-americké geopolitické rivality v indo-pacifické oblasti / Structural Violence and Great Power Competition: The Effects of Sino-U.S. Geopolitical Rivalry in the Indo-Pacific

Iocovozzi, James January 2020 (has links)
Structural Violence and Great Power Competition: The Effects of Sino-U.S. Geopolitical Rivalry in the Indo-Pacific Abstract This paper examines the effects of the ongoing strategic rivalry between China and the United States for influence over the Indo-Pacific in order to demonstrate the negative impacts upon structural violence within the region. Using an amalgamation from various authors, this paper establishes a definition and set of criteria for the presence of structural violence which are then applied to the cases of Vietnam, Myanmar, and Japan. By correlating the mechanisms with which China and the United States garner influence with the specific consequences for the prevalence and severity of structural violence, this paper illustrates that the ongoing geopolitical rivalry poses considerable threats to all Indo-Pacific nations regardless of their development status or social, political, economic, and geographic characteristics. Results indicate that the extent of each country's structural violence was directly or indirectly affected by the presence of foreign involvement, and that different levels of alignment or independence can serve to reduce or exacerbate these effects. Furthermore, evidence indicated that China's methods pose a more immediate threat to induvial countries, but that the United...
12

Ecological stability of Indo-Pacific coral reefs during Quaternary climatic fluctuations

Mewis, Heike 15 March 2016 (has links)
Rezente Korallenriffe sind einer ganzen Reihe von Bedrohungen ausgesetzt. Das Pleistozän bietet die Gelegenheit Veränderungen an Korallenriffgemeinschaften durch Klimaschwankungen hinweg zu studieren und mit heutigen Riffen zu vergleichen. Am besten sind pleistozäne Riffe in der Karibik untersucht, während aus dem Indo-Pazifik, der über eine deutlich höhere Biodiversität verfügt, bisher nur wenige quantitative Studien vorliegen. Frühere Studien zeigen eine erstaunliche Stabilität und Langlebigkeit der Korallengemeinschaften hinsichtlich Diversität und taxonomischer Zusammensetzung trotz extremer Meeresspiegelschwankungen und starker klimatischer Veränderungen im Quartär. Die vorliegende Arbeit behandelt zwei Regionen, aus der quantitative Daten auf Artniveau über die Zusammensetzung der fossilen Korallengemeinschaften bisher weitestgehend fehlten: das tropische Vanuatu (Südpazifik) und der subtropische Sinai, Ägypten (nördliches Rotes Meer). In Vanuatu sind mindestens 5 fossile Riffterrassen mit einem Alter von etwa 5000 - 400.000 Jahren überliefert, von denen 4 detailliert untersucht werden konnten. Veränderungen in der Diversität wurden sowohl lateral als auch vertikal nur mit unterschiedlichen Riffhabitaten in Verbindung gebracht. Die Riffe waren insgesamt über die Interglaziale bin ins mittlere Holozän hinweg stabil. Nur die Gattung Acropora scheint erst in den letzten 96.000 Jahren häufiger zu werden. In Ägypten wurden Daten aus der jüngsten interglazialen Terrasse (MIS 5e, ~125.000 Jahre) mit rezenten Daten aus dem Roten Meer verglichen und eine Migration von Arten nach Norden während des letzten Interglazials belegt. Diese Beobachtung unterstützt frühere Arbeiten, die eine Verschiebung der Riffdiversität in höhere Breiten verbunden mit einer Abnahme der Diversität in niederen Breiten aufzeigten, sowie Studien, die das nördliche Rote Meer als mögliches Refugium für Korallen im Zuge der weiteren Klimaerwärmung sehen. / The Pleistocene provides the opportunity to study changes of coral reef communities through times of climate change, and to compare fossil to recent reefs. Whereas Pleistocene reefs from the Caribbean are well studied and understood, the much larger Indo-Pacific region with a greater coral diversity is represented by only a few quantitative studies on community ecology. Previous studies observed an astonishing persistence and stability in community composition and diversity throughout several interglacial episodes until today, which is contradictory to the claim that recent coral reefs are especially sensitive to climate change. The present study deals with two Indo-Pacific regions that so far lacked quantitative data of fossil reef communities: tropical Vanuatu (Coral Sea) and subtropical Sinai, Egypt (northern Red Sea). In Vanuatu at least seven fossil reef terraces with ages between 5,000 and 400,000 years are preserved, of which four could be studied in more detail. A great variability was observed among terraces and especially among sub-environments within terraces. Reefs remained stable in terms of diversity throughout the Pleistocene and Holocene but it seems that the dominance of the coral genus Acropora is a fairly recent phenomenon in Vanuatu, because this genus does not play a large role in terraces older than 96,000 years (MIS 5c). In Egypt quantitative and binary data from the last interglacial episode (MIS 5e) were compared with data from the recent Red Sea and adjacent regions. These show a northward migration of coral taxa during the last MIS5e. This observation confirms earlier studies that demonstrated a range expansion of tropical reef communities towards higher latitudes, and supports studies that suggest the northern Red Sea and especially the Gulf of Aqaba as future refuge for corals during climate warming. These results indicate that coral reefs were able to cope with dramatic environmental changes in the absence of anthropogenic impact.
13

Heat and salinity transport across the Indonesian Archipelago over the last 270,000 years : new insights into the orbital and millennial dynamics of the Indonesian Throughflow and the Intertropical Convergence Zone / Transport de chaleur et de salinité à travers l'archipel indonésien au cours des 270 000 dernières années : nouveaux enregistrements de la dynamique orbitale et millénaire du flux indonésien et de la zone de convergence intertropicale

Pang, Xiaolei 14 October 2019 (has links)
Ce travail avait pour but de reconstituer l'évolution de la température et du δ¹⁸O des eaux de surface et des eaux de la thermocline dans la Warmpool indo-pacifique (IPWP) en combinant la thermométrie Mg / Ca et la mesure des isotopes stables de l'oxygène sur des foraminifères planctoniques de surface et de sub-surface prélevés dans des carottes de sédiments situées dans l'océan Indien tropical oriental. Ce travail a permis de ré-évaluer les effets des différentes méthodes de nettoyage et de la dissolution in situ sur la thermométrie Mg/Ca des foraminifères planctoniques, mettant en évidence la nécessité de corrections différentes suivant les espèces. L’évolution de l’IPWP au cours des 270 000 dernières années a été reconstituée. Les résultats indiquent que le δ¹⁸O des eaux de surface reflètent principalement l'advection latérale plutôt que l'historique des précipitations régionales, et suggèrent que l'hydrologie de surface IPWP est contrôlée par la migration latitudinale de la zone de convergence intertropicale aux échelles de temps orbitales mais aussi en réponse aux événements climatiques abrupts de l'hémisphère nord (eg. événements de Heinrich). Les variations de salinité de surface sont étroitement corrélées aux changements d’export vers l’Atlantique au niveau du Courant des Aiguilles (Sud de l’Afrique). Puis, les changements dans le transport des eaux de la thermocline issues de l’ITF vers l'océan Indien ont été étudiés. Les résultats montrent que le transport était plus faible pendant les glaciations (ie. MIS 6 et 4-2) que pendant les périodes interglaciaires (ie. MIS 7, MIS 5 et Holocène) et exerçaient une influence significative sur les changements de la température de la thermocline dans l'Océan Indien. / This work aimed at reconstructing the late Quaternary evolution of surface and thermocline temperature and ocean surface water δ¹⁸O in the Indo-Pacific Warm Pool by combining Mg/Ca-thermometry and stable oxygen isotope analyses on surface and thermocline-dwelling planktonic foraminifers retrieved from sediment cores in the eastern tropical Indian Ocean. This study allowed to re-evaluate the effects of different cleaning methods and in-situ dissolution on the Mg-thermometry of planktonic foraminifers, evidencing the need for species-dependent corrections. Then, the IPWP evolution over the last 270,000 years has been explored. Results indicate that surface water δ¹⁸O chiefly reflects lateral advection rather than local precipitation history, and suggest that surface IPWP hydrology is controlled by the latitudinal migration of the Intertropical Convergence Zone at orbital timescale as well as during abrupt northern hemisphere climatic events (i.e. Heinrich events). Ocean surface salinity in the IPWP and Agulhas leakage region varied synchronously, implying their teleconnection through oceanic and atmospheric circulation. Moreover, changes in the transport of thermocline water to the Indian Ocean by the Indonesian Throughflow (ITF) have been reconstructed. Results show that thermocline water transport was weaker during glacials (i.e. MIS 6 and 4-2) than during interglacials (MIS 7, MIS 5 and Holocene), and exerted significant influence on Indian Ocean TWT change.

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