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 31 for “"Joint inversion"”.
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Model Uncertainties and Joint Inversion in Geophysics
… models for the case of di erent data types and jointly correlated parameters. We show that the associated joint likelihood functions are coupled and that the errors are heavily correlated with the unknowns. We also show that the assimilation of di erent measurement modalities with properly …
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Individual and joint inversion of surface wave tomography for near-surface applications
L'abstract è presente nell'allegato / the abstract is in the attachment
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Seismic Investigation on Temporal Structural Changes and Joint Inversion of Sedimentary and Crustal Structure Beneath North China
… other basins located within North China Plain. A joint inversion of Rayleigh wave phase velocity and ellipticity are applied to obtain a high-resolution S-wave velocity model for the North China region. The results show a good correlation between sedimentary structure and sub-terranes geology, …
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Joint inversion of density and resistivity logs for the improved petrophysical assessment of thinly-bedded clastic rock formations
… approximately equal to 1 foot), a new joint inversion procedure is introduced in this thesis that effectively combines borehole measurements of density and induction resistivity. The objective of the inversion is to reduce shoulder-bed effects on the interpretation of porosity and …
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Imaging the crust and uppermost mantle of north central Alaska using the joint inversion of ambient seismic noise correlation and receiver function
Seismic velocity models obtained from the joint inversion of ambient seismic noise correlation and receiver function analysis show a representation of the crustal and uppermost mantle velocity structure in north central Alaska. Due to the lack of station coverage and inhospitable terrain, the …
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Mitigating the Problem of Non-uniqueness in Fluid-flow Modeling
… complemented the fluid flow data in different joint inversion methods. sing self-potential data allows the detection of fractures with higher confidence. The seismic data was used in a cross-gradient joint inversion scheme to constrain the inversion of fluid flow data. The joint inversion …
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The rupture process of recent tsunamigenic earthquakes by geophysical data inversion
… the source process is to have recourse to the inversion of geophysical data that are available. Tsunami data, moreover, are useful to constrain the portion of the fault area that extends offshore, generally close to the trench that, on the contrary, other kinds of data are not able to …
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Seismic studies of 3-D elastic and anelastic structure of crust and upper mantle in Western China
… and body-wave travel times, as well as joint inversions of these datasets utilizing neighborhood searching algorithm. We propose a generalized H-κ method with harmonic correction on receiver functions to provide a better estimation of the crustal thickness (H) and Vp/Vs ratio (κ). Our …
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Imaging and interpreting seismic heterogeneity in the North American lithosphere
… and geochemical variations. In this Thesis I jointly interpret inverse modeling of seismic data and forward modeling of chemical and thermodynamic data in order to investigate the origins of seismic heterogeneity within the cratonic lithosphere. I present a joint inversion of body and surface …
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A Multicomponent Walkaway Vertical Seismic Profile Experiment in a Heavy Oil Reservoir
… image and pre-stack gathers were made for inversion and AVO analysis. A common shot reflectivity gather was also created for AVO study at the VSP well location. P and S-wave impedance, reflectivity, Vp/Vs and density were studied. AVO attributes and their crossplots were analyzed. …
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Development of Deep Site Specific and Reference Shear Wave Velocity Profiles in the Canterbury Plains, New Zealand
… ratio measurements. A multi-mode, multi-method joint inversion process, which included Rayleigh and Love wave dispersion and horizontal to vertical spectral ratio data, was used to estimate the shear wave velocity profiles at each site. A-priori geologic information was utilized in defining …
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A Bayesian Reappraisal of Australian Crustal Heat Flow and Temperature
… they advances us on the pathway towards genuine joint-inversion involving geothermal data. The quantification of uncertainty distributions on geothermal data sets provides the means to calculate the degree with which a given earth model is consistent with available geothermal data. In doing so, …
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A Bayesian Reappraisal of Australian Crustal Heat Flow and Temperature
… they advances us on the pathway towards genuine joint-inversion involving geothermal data. The quantification of uncertainty distributions on geothermal data sets provides the means to calculate the degree with which a given earth model is consistent with available geothermal data. In doing so, …
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Remote Sensing of 21st Century Water Stress for Hazard Monitoring in California
… storage change, I also introduce a new method to jointly invert elastic vertical displacements at GNSS stations with water storage anomalies from the Gravity Recovery and Climate Experiment (GRACE) to solve for water storage changes from 2003-2016 over California. Finally, I expand on this joint …
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Seismic study of the crust and upper mantle structure in eastern Asia using ambient noise correlation and earthquake data
… correlation and apply them in eastern Asia. A joint inversion scheme using first and secondary Pg arrivals and Pn arrivals is developed to determine the crustal and uppermost mantle P wave velocity and the depth of Moho discontinuity. This method addresses the trade-off issue between the media …
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LAKEMAGING: GEOPHYSICAL DATA INTEGRATION FOR GROUNDWATER MODELLING
… groundwater modelling. The first part addresses joint inversion of concordant, discordant, and geologically constrained datasets. It shows that combining datasets with complementary sensitivities can reduce non-uniqueness and improve subsurface characterization, while robust inversion strategies …
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Theoretical and computational studies in seismic tomography
… of lengthscales, with the method of waveform inversion being a promising and relatively recent development. In this work, we present new theoretical methods which may contribute to the study and solution of seismic tomography inverse problems. In particular, we set out the mathematical …
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Geophysical imaging methods for analysis of the Krafla Geothermal Field, NE Iceland
Joint geophysical imaging techniques have the potential to be reliable methods for characterizing geothermal sites and reservoirs while reducing drilling and production risks. In this study, we applied a finite difference tomography method and a double-difference tomography method to image the P- …
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