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 13 of 13 for “"Lithosphere asthenosphere boundary."”.
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Seismic imaging of the lithosphere-asthenosphere boundary with a dense broadband array in central California
… the lateral extent of interruption of the lithosphere-asthenosphere boundary (LAB). The study area spans the location of two plausible origins for the anomaly, the Monterey microplate (Wang et al., 2013) and Sierra Nevada batholith (Ducea & Saleeby, 1998). Results include 918 binned …
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Melt generation in the Earth's mantle at Convergent Plate Margins
… arc were formed by mantle upwelling near the lithosphere-asthenosphere boundary caused by plate subduction, not by a mantle plume (Chapter 4). A geodynamic and petrologic study (Chapter 5) of asthenospheric flow at the margins of thick continental lithosphere reveals small degree melts of the …
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Characterization of secondary mantle convection from geophysical data and models
… SEMUCB-WM1, SAVANI and S40RTS to infer the lithosphere/asthenosphere boundary, and the destabilization of the lithosphere, induced by secondary mantle convection. Former studies, based on numerical and experimental models report that secondary convection would occur as sub-lithospheric …
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Receiver function study in northeast Tibet and adjacent boundaries
… of the Moho geometry and constraints on the lithosphere-asthenosphere boundaries (LAB). The average crustal thickness is about 50km for the northeastern corner of the Tibetan plateau. The deepest Moho is found along the Kunlun Fault zone in the northern Tibetan plateau. We also observed the …
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Testing the Utility of S Receiver Function Analysis For Mapping Seismic Discontinuities In the Sierran Lithosphere
… mapping seismic discontinuities of the Sierran lithosphere for implications on delamination. Efforts focus primarily on imaging the topography of the Sierran Moho to bolster recent P receiver function findings and detecting the Sierran basal low velocity zone, which often characterizes the …
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Geophysical and petrological constraints on ocean plate dynamics
… and petrological methods. Ocean crust and lithosphere forms at mid-ocean ridges as the underlying asthenosphere rises, melts, and flows away from the ridge axis. In Chapters 2 and 3, I present the results from partial melting experiments of mantle peridotite that were conducted in order to …
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Geophysical and petrological constraints on ocean plate dynamics
… and petrological methods. Ocean crust and lithosphere forms at mid-ocean ridges as the underlying asthenosphere rises, melts, and flows away from the ridge axis. In Chapters 2 and 3, I present the results from partial melting experiments of mantle peridotite that were conducted in order to …
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Gravity constraints on extension and magmatism in the northernmost Rio Grande rift, northern Colorado
… construct a forward gravity model to constrain lithosphere and upper asthenosphere density structure. The results are illustrated along three E-W oriented cross sections cutting Middle Park, the Rabbit Ears Range and North Park. The observed gravity field along these profiles correlate with the …
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SEISMIC VELOCITY, RADIAL ANISOTROPY IN THE CRUST AND UPPER MANTLE OF NORTHEASTERN TIBETAN PLATEAU FROM SURFACE WAVE TOMOGRAPHY
… and partial melting resulted from localized asthenosphere upwelling after the delamination of a thick lithosphere root beneath the bend. In the second part of the dissertation, a 3-D SH velocity (VSH) model was obtained from the Love wave phase velocities at 13 periods from 20 to 91 s, and …
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Enhanced imaging of deep lithospheric and shallow near surface structures through innovations in seismic interferometry and array processing.
… from a sharp, negative velocity gradient at the Lithosphere-Asthenosphere Boundary (LAB) at approximately 90 km depth. The detection of this event in a relatively high-frequency band, combined with its positive polarity in autocorrelograms, indicates a steep velocity gradient at the LAB …
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Seismic Imaging of the Global Asthenosphere using SS Precursors
The asthenosphere, a weak layer beneath the rigid lithosphere, plays a fundamental role in the operation of plate tectonics and mantle convection. While this layer is often characterized by low seismic velocity and high seismic attenuation, the global structure of the asthenosphere remains poorly …
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Surface heat flow and lithospheric thermal structure of the northwestern Arabian Plate
… for modeling the thermal structure of the lithosphere. Changes in the qs over a distinct lithospheric unit are normally directly reflecting changes in the crustal composition and therewith the radiogenic heat budget (e.g., Rudnick et al., 1998; Förster and Förster, 2000; Mareschal and …
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The geothermal potential of Luxembourg
… by the geophysically-estimated depth of the lithosphere–asthenosphere boundary (LAB) defined by the 1300 °C isotherm. A LAB depth of 100 km, as seismically derived for the Ardennes, provides the best fit with the measured surface heat flow. The resulting mantle heat flow amounts to ∼40 mW …