Global ETD Search
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Showing 1 to 11 of 11 for “"travel time tomography"”.
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P- and S- wave tomography of the crust and uppermost mantle in China and surrounding areas
… uppermost mantle in China from the P- and S-wave travel-time tomography. The main contributions of this research are: 1) introducing the adaptive moving window method to obtain 2338 1D P and S models in China; 2) introducing a tomographic method to perform the 3D body wave travel-time tomography …
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Seismic Site Characterization for the Deep Science and Engineering Laboratory (DUSEL) at Kimballton, Virginia
… processing techniques included the use of travel time tomography to accurately constrain near surface velocities, the use of 2D median filters to remove ground roll, and stacking only offsets exceeding 500 m. Interpretation of seismic data supports a triplicated stratigraphic section caused …
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Entwicklung einer simultanen refraktions- und reflexionsseismischen 3D-Laufzeittomographie mit Anwendung auf tiefenseismische TRANSALP-Weitwinkeldaten aus den Ostalpen
A 3D refraction and reflection seismic travel time tomography was developed on the basis of the widespread Local Earthquake Tomography (LET) method SIMULPS. To include crustal scale refraction seismic observations in the inversion the accuracy of this method was adjusted for long ray paths and high …
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Seismic Imaging of a Granitoid-Greenstone Boundary in the Paleoarchean Pilbara Craton
… Seismic velocity models created using travel-time tomography suggest a thin weathering layer overlying slightly fractured crystalline rocks. These fractures close within 200-300 m depth, and velocity reaches bedrock speeds consistent with expected values of granitoids to the west and …
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Probing the interior of an active volcano: Three-dimensional seismic tomography at Montserrat
… middle crust, which can influence the style and time-scales of eruptions. Seismic tomography can provide detailed resolution of the physical characteristics of complex three-dimensional structures in the subsurface, and has been successfully employed at several active volcanoes to constrain the …
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The tectonics and three-dimensional structure of spreading centers--microearthquake studies and tomographic inversions
… studies or tomographic inversion of travel times. Results of these studies are used to constrain the spatial variability of physical properties and processes beneath the axis of spreading and, together with other observations, the temporal characteristics of crustal accretion and …
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Continental Arc Processes in British Columbia and Earthquake Processes in Virginia: Insights from Seismic Imaging
Travel times from a refraction and wide-angle reflection seismic survey across the Coast Plutonic Complex and Stikine terrane of British Columbia were inverted to derive two dimensional P and S-wave seismic velocity models of the crust and uppermost mantle. A felsic upper crust and a felsic to …
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Continental Tectonics from Dense Array Seismic Imaging: Intraplate Seismicity in Virginia and a Steep Cratonic Margin in Idaho
… reflection and refraction seismic P- and S-wave traveltimes to determine a seismic velocity model of the crust beneath this part of the U.S. Cordillera. We imaged a narrow, steep velocity boundary within the crust that juxtaposes the Blue Mountains accreted terranes and the North American craton …
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The tectonics and three-dimensional structure of spreading centers : microearthquake studies and tomographic inversions
… studies or tomographic inversion of travel times. Results of these studies are used to constrain the spatial variability of physical properties and processes beneath the axis of spreading and, together with other observations, the temporal characteristics of crustal accretion and …
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Tomographic inversion of Pn travel times in western China
… geologists and geophysicists for many years. Pn tomography is a useful tool to explore the heterogeneity of the Earth's interior. In this study, we obtain a Pn velocity image and the crustal thickness for western China using a Pn tomographic inversion based on a large collection of Pn travel time …