Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 56 for “"Rifts"”.
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Magma genesis beneath active continental rifts
… evidence for low-density mantle underlying both rifts, have traditionally been interpreted as evidence for anomalously hot mantle plumes actively rising from the deep mantle beneath both regions. However, in light of increasing evidence that these mantle structures may also be chemical in nature, …
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The structure and seismicity of Icelandic rifts
… Iceland and shallows into the active volcanic rifts. This extensive feature suggests high mid-crustal temperatures and a high temperature-gradient between the extrusives of the upper crust and the intrusive mid-to-lower crust in Iceland.
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Magmatic volatiles at rifts and arcs: Sources and fractionation effects
… why arc magmas are more oxidized than those at rifts. Finally, the S retained in the subducted slab is isotopically light, potentially carrying the signature of microbial life into the deep mantle.
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Topography and tectonics of the intersections of fracture zone with central rifts.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1969.
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Joule heating and pore pressure evolution, magmatic intrusions at continental rifts, and microseisms in Yellowstone Lake
The goal of this thesis is to investigate research topics related to geothermal resources. Chapter 1 introduces the thesis and motivates the need to study research topics in relevant geothermal environments, and develop new technologies to economically extract heat from these resources. In Chapter …
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Joule Heating and Pore Pressure Evolution, Magmatic Intrusions at Continental Rifts, and Microseisms in Yellowstone Lake
The goal of this thesis is to investigate research topics related to geothermal resources. Chapter 1 introduces the thesis and motivates the need to study research topics in relevant geothermal environments, and develop new technologies to economically extract heat from these resources. In Chapter …
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Tracing mantle degassing along the East African Rift using He and C isotopes: a geospatial approach
… helium is seen along the Kenyan and Kivu rifts, due to either diluted plume influence and/or input from DMM or SCLM (Sub-Continental Lithospheric Mantle). Plume-like helium is seen in Rungwe, indicating deep-mantle input. This study introduced carbon as a concurrent tracer, which showed …
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Effects of Initial Thermal Structure on the Evolution of Continental Rifting
… and processes that control the evolution of rifts remain enigmatic. Previous research suggests that the initial thermal structure may have a first order control on the evolving styles of these systems. This project examines the impact of the initial thermal structure on the spatial and …
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Seismic Studies of the East African Rift System and the Tibetan Plateau: Implications for the Rheology of Lithosphere and the Evolution of Rifts in Continents
Additional evidence for this conclusion comes from my study of eleven intracontinental earthquakes, with magnitudes ranging from 4.9 to 6, which occurred in the mantle beneath the western Himalayan syntaxis, the western Kunlun Mountains, and southern Tibet (near Xigaze). High-resolution seismic …
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William Vander Zalm to Rita Johnston : the 1991 leadership choice of the Social Credit Party of British Columbia
… convention, the party was divided by numerous rifts which had developed during the 1986 leadership convention and since that event. Rather than heal the rifts, the 1991 leadership convention exacerbated them. Thus, as the 1991 leadership convention closed the party was more divided than when …
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CENOZOIC EXTENSION OF THE LAKE TANGANYIKA RIFT, EAST AFRICA: STRUCTURES, TECTONOSTRATIGRAPHY AND PALEOENVIRONMENTAL RECONSTRUCTION
<p>Active continental rifts are ideal sites for understanding the break-up of continents, and long-lived rift lake environments are known as important reservoirs for endemic communities and biodiversity. The sedimentary fill of extensional continental rifts within the East Africa Rift System (EARS) …
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Memorial Museums: Politics, Spectacle and Interpretation
… are failing to address and challenge the social rifts and exclusion that characterized the countries’ pasts and could foster exclusion and social rifts today. Memorial museums may encourage empathy with their depictions of suffering, but they often lack accurate historical and political context; …
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Investigating the Kinematics and Dynamics of Strain Localization in the Northern Western Branch of the East African Rift System
Continental rifts are thought to be formed by repeated episodes of magmatism, reactivation of pre-existing structures, or a combination of both. Continental rifts are evidence of a divergent plate boundary, where tectonic plates are breaking apart. The northern Western Branch of the East African …
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Investigating volcano tectonic interactions in the Natron Rift of the East African Rift System
… of currently and previously active rifts, scientists have discovered considerable interactions between these tectonic and magmatic processes during a rift's evolution; however questions remain about these interactions especially in youthful stages of rifts. We investigate an early …
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The flow and fracture of Antarctic Ice Shelves
… of active full-thickness fractures, known as rifts. This dataset provides a mechanical framework with which we can analyze dynamic change, allowing us to quantify surface deformation with radar remote sensing. Lastly, Chapter 4 presents a fatigue-crack growth model for active rifts. This …
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The Flow and Fracture of Antarctic Ice Shelves
… of active full-thickness fractures, known as rifts. This dataset provides a mechanical framework with which we can analyze dynamic change, allowing us to quantify surface deformation with radar remote sensing. Lastly, Chapter 4 presents a fatigue-crack growth model for active rifts. This …
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The United States Military Realignment on Okinawa
… forces on Okinawa has caused minor, yet growing, rifts in the stable United States-Japanese alliance. Current plans to shift American military forces from Okinawa to locations throughout the Pacific do not take into account the historical or geostrategic factors for their stationing in Japan. This …
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Tectonic Setting, Structure, and Seismic Stratigraphy of the Apalachicola Rift and its Overlying Sag Basin in the Northeastern Gulf of Mexico
… of the AR-Elbow rift trend with the marginal rifts bordering oceanic crust ~200 km to the southwest as indicating that both sets of rifts are part of the second phase of rifting in GOM that was related to the late Jurassic, counterclockwise rotation of the Yucatan block.
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EU security cooperation and the transatlantic relationship
… in spite of several minor, and not so minor rifts, the transatlantic relationship remained solid and has better prospects for the future. In addition, by examining the relations of France and Poland with the U.S, the dissertation will indicate that, although there are differences in the …
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A Location in Parts
… be born out of investigating these contemporary rifts in labor practices, and whether conceptual nodes of thinking the ‘outlandish’ can help us create new (er) pasts, presents and futures with greater empathy.
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