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 206 for “"upper mantle"”.
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Structure and anisotropy of the upper mantle
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1995.
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Structure and dynamics of the Pacific upper mantle
… the structure and dynamics of the Pacific upper mantle. We invert band-center travel times of ScS reverberations and frequency-dependent travel times of direct S phases, upper-mantle guided waves such as SS and SSS, and the R1 and G1 surface waves for the 2D composite structure in the plane …
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Structure and dynamics of the Pacific upper mantle
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1998.
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Reflectors in upper mantle above the deep earthquakes.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1974.
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Anisotropy and the structural evolution of the oceanic upper mantle
… to detect the change in the structure of the upper mantle as the age of the sea-floor increases away from the mid-ocean ridge. Using the single station method, the group and phase velocities of Rayleigh waves were measured for 78 paths in the east Pacific. The focal mechanisms of the source …
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Tectonics, cru[s]tal and upper mantle structures of Taiwan
<p>The crustal structures of Taiwan and the upper mantle structures in the vicinity of Taiwan have been determined for the first time through body wave studies. Travel times of local crustal events recorded both at the portable and the Telemetered Seismograph Network of Taiwan (TSNT) determine the …
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The X-discontinuity: Seismic signatures of a heterogeneous upper mantle
… large-scale changes in composition like the core-mantle boundary. Widely distributed previous seismic observations of localised reflectors in the upper mantle have been termed the X-discontinuity (X; 230-350 km depth) and allude to the widespread presence of chemical heterogeneity, but the exact …
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Seismic-wave attenuation and the state of the upper mantle.
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1971.
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Crust and upper mantle structure of the northeastern United States
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1980.
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Anisotropy and the structural evolution of the oceanic upper mantle.
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1974.
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Geochemical and rheological constraints on the dynamics of the oceanic upper mantle
I provide constraints on mantle convection through observations of the rheology and composition of the oceanic upper mantle. Convection cannot be directly observed, yet is a fundamental part of the plate tectonic cycle. Relative motion among plates is accommodated by localized deformation at their …
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Teleseismic P Wave Attenuation in the Upper Mantle Beneath the United States
… to examine seismic attenuation patterns in the upper mantle. 2.5 million inter-station P wave spectral ratios were inverted for maps of relative t* variations across the United States in multiple frequency bands between 0.08 and 2 Hz. Broader frequency bands are associated with lower magnitude …
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Receiver function analysis of crustal and upper mantle structure beneath Southern Africa
Bibliography: leaves 101-111.
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Experimental constraints on the rheological behavior of olivine at upper mantle conditions
… than the crust, the inaccessibility of the mantle and core present a different challenge: unraveling the physical behavior of materials at conditions beyond our intuitive, observational, and experimental grasp. Among the most persistent of problems has been determining the influence of …
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Geochemical and rheological constraints on the dynamics of the oceanic upper mantle
I provide constraints on mantle convection through observations of the rheology and composition of the oceanic upper mantle. Convection cannot be directly observed, yet is a fundamental part of the plate tectonic cycle. Relative motion among plates is accommodated by localized deformation at their …
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An investigation of the upper mantle P-velocity models using synthetic seismograms.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Geology and Geophysics, 1968.
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Geobarometry, phase relations and elasticity of eclogite under conditions of Earth’s upper mantle
… equilibration pressures recorded by natural mantle eclogites from various xenolith locations covering a wide pressure, temperature, and compositional range. The results seem to indicate that many eclogite xenoliths fall towards the hotter side of the range of geothermal temperatures displayed …
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Silicon and oxygen self-diffusion in forsterite and implications to upper-mantle rheology
… should be reconsidered. The viscosity in the upper mantle calculated from DSi continuously decreases with increasing depth without appearing a minimum zone by mineral hydration, and therefore, the asthenosphere softening cannot be caused by water effect. The CH2O differences between the source …
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