Dissertations / Theses on the topic 'Geophysics'
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Shipp, Richard Michael. "Two-dimensional full wavefield inversion of wide-aperture marine seismic streamer data." Thesis, University of Cambridge, 2000. https://www.repository.cam.ac.uk/handle/1810/251747.
Full textJohansson, Linnéa. "Modelling and interpretation of VTEM data from Soppero, Sweden." Thesis, Luleå tekniska universitet, Geovetenskap och miljöteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-64879.
Full textPairmain, D. "Image processing in geophysics." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375293.
Full textCheung, See Nga Cecilia. "Experimental deformation in sandstone, carbonates and quartz aggregate." Thesis, State University of New York at Stony Brook, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3717020.
Full textThe first part of my thesis is mainly focused on the effect of grain size distribution on compaction localization in porous sandstone. To identify the microstructural parameters that influence compaction band formation, I conducted a systematic study of mechanical deformation, failure mode and microstructural evolution in Bleurswiller and Boise sandstones, of similar porosity (∼25%) and mineralogy but different sorting. Discrete compaction bands were observed to develop over a wide range of pressure in the Bleurswiller sandstone that has a relatively uniform grain size distribution. In contrast, compaction localization was not observed in the poorly sorted Boise sandstone. My results demonstrate that grain size distribution exerts important influence on compaction band development, in agreement with recently published data from Valley of Fire and Buckskin Gulch, as well as numerical studies.
The second part aimed to improve current knowledge on inelastic behavior, failure mode and brittle-ductile transition in another sedimentary rock, porous carbonates. A micritic Tavel (porosity of ∼13%) and an allochemical Indiana (∼18%) limestones were deformed under compaction in wet and dry conditions. At lower confining pressures, shear localization occurred in brittle faulting regime. Through transitional regime, the deformation switched to cataclastic flow regime at higher confining pressure. Specifically in the cataclastic regime, the (dry and wet) Tavel and dry Indiana failed by distributed cataclastic flow, while in contrast, wet Indiana failed as compaction localization. My results demonstrate that different failure modes and mechanical behaviors under different deformation regimes and water saturation are fundamental prior to any geophysical application in porous carbonates.
The third part aimed to focus on investigating compaction on quartz aggregate starting at low (MPa) using X-ray diffraction. We report the diffraction peak evolution of quartz with increasing pressures. Through evaluating the unit cell lattice parameters and the volume of the quartz sample, macroscopic stress and strain were resolved. Moreover, we observed quartz peak broadened asymmetrically at low pressure, such extent is more prominent in axial than in radial direction. Our evaluation on peak [101] (highest intensity among peaks) demonstrated that full width at half maximum can be a good proxy for microscopic stress distribution. We observed deviations in the pressure-volume curves at P = ∼0.4 GPa and speculated that it was the point of which onset of grain crushing and pore collapse occur in quartz. This is on the same order of which onset of grain crushing (commonly known as P*) is observed in sandstones in the rock mechanics literature. This demonstrated that there is potential in estimating grain crushing and pore collapse pressure with our technique.
Perez, Altimar Roderick. "Brittleness estimation from seismic measurements in unconventional reservoirs| Application to the Barnett shale." Thesis, The University of Oklahoma, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3617030.
Full textBrittleness is a key characteristic for effective reservoir stimulation and is mainly controlled by mineralogy in unconventional reservoirs. Unfortunately, there is no universally accepted means of predicting brittleness from measures made in wells or from surface seismic data. Brittleness indices (BI) are based on mineralogy, while brittleness average estimations are based on Young's modulus and Poisson's ratio. I evaluate two of the more popular brittleness estimation techniques and apply them to a Barnett Shale seismic survey in order to estimate its geomechanical properties. Using specialized logging tools such as elemental capture tool, density, and P- and S wave sonic logs calibrated to previous core descriptions and laboratory measurements, I create a survey-specific BI template in Young's modulus versus Poisson's ratio or alternatively λρ versus μρ space. I use this template to predict BI from elastic parameters computed from surface seismic data, providing a continuous estimate of BI estimate in the Barnett Shale survey. Extracting λρ-μρ values from microseismic event locations, I compute brittleness index from the template and find that most microsemic events occur in the more brittle part of the reservoir. My template is validated through a suite of microseismic experiments that shows most events occurring in brittle zones, fewer events in the ductile shale, and fewer events still in the limestone fracture barriers.
Estimated ultimate recovery (EUR) is an estimate of the expected total production of oil and/or gas for the economic life of a well and is widely used in the evaluation of resource play reserves. In the literature it is possible to find several approaches for forecasting purposes and economic analyses. However, the extension to newer infill wells is somewhat challenging because production forecasts in unconventional reservoirs are a function of both completion effectiveness and reservoir quality. For shale gas reservoirs, completion effectiveness is a function not only of the length of the horizontal wells, but also of the number and size of the hydraulic fracture treatments in a multistage completion. These considerations also include the volume of proppant placed, proppant concentration, total perforation length, and number of clusters, while reservoir quality is dependent on properties such as the spatial variations in permeability, porosity, stress, and mechanical properties. I evaluate parametric methods such as multi-linear regression, and compare it to a non-parameteric ACE to better correlate production to engineering attributes for two datasets in the Haynesville Shale play and the Barnett Shale. I find that the parametric methods are useful for an exploratory analysis of the relationship among several variables and are useful to guide the selection of a more sophisticated parametric functional form, when the underlying functional relationship is unknown. Non-parametric regression, on the other hand, is entirely data-driven and does not rely on a pre-specified functional forms. The transformations generated by the ACE algorithm facilitate the identification of appropriate, and possibly meaningful, functional forms.
TROTTER, BENNETT. "Pore Pressure Prediction in the Point Pleasant Formation in the Appalachian Basin, in parts of Ohio, Pennsylvania, and West Virginia, United States of America." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1524213528591632.
Full textBey, Scott Michael. "Reservoir Characterization and Seismic Expression of the Clinton Interval over Dominion's Gabor Gas Storage Field in North-East Ohio." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1347391687.
Full textPersson, Kjell. "Integrated geophysical-geochemical methods for archaeological prospecting." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279.
Full textChapel, Brian Ernie. "Digital disk recorder for geophysics." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24592.
Full textScience, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
Garrick-Bethell, Ian 1980. "Early lunar geology and geophysics." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/47845.
Full textIncludes bibliographical references.
Despite a number of human and robotic missions to the Moon, there are still important unanswered questions about its early evolution, and how it came to be the object we observe today. Here we use observational, experimental, and theoretical techniques to examine three important events that took place early in lunar history and have left a lasting signature. The first event is the formation of the largest basin on the Moon, the South Pole-Aitken Basin. We develop a systematic method to define the previously unknown boundaries of this degraded structure and quantify its gross shape. We also combine a number of remote sensing data sets to constrain the origin of heat producing elements in its interior. The second event we examine is the evolution of the lunar orbit, and the coupling between the Moon's early geophysical properties and the growth of orbital eccentricity. We use analytical models for tidal deformations and orbit evolution to show that the shape of the Moon suggests its early orbit was highly eccentric. However, we are also able to explain the presently high eccentricity entirely by traditional, secular tidal growth while the early Moon was hot. The third event we examine is the magnetization of lunar samples. We perform extensive paleomagnetic measurements of an ancient, deep-seated lunar sample, and determine that a long-lived magnetic field like that of a core dynamo is the most plausible explanation for its magnetic remanence. In sum, the earliest portion of lunar history has been largely obscured by later geologic events, but a great deal can still be learned from this formative epoch.
by Ian Garrick-Bethell.
Ph.D.
Spurr, Charles. "Seismic Analyses of the Crust and Moho beneath the Foreland Fold and Thrust Belt of the Southern Urals, Russia." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1441883731.
Full textShank, Jared Wyatt. "A geophysical investigation to locate missing graves utilizing ground penetrating radar, electromagnetic, and magnetic methods." Wright State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=wright1389704983.
Full textTorikka, Niklas. "3D Modelling of TEM Data : from Rajapalot Gold-Cobalt prospect, northern Finland." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-75756.
Full textRajapalot guld-kobolt-projektet i norra Finland är en spännande, relativt ny upptäckt som fortfarande undersöks med hopp om att starta gruvbrytning i framtiden. Området upptäcktes via en IP/Resistivitets-undersökning under 2013. Omfattande geofysiska undersökningar har avgränsat flera elektromagnetiska anomalier, varav en, döpt Raja, är den anomali som den här masteruppsatsen är uppbyggd kring. En TEM-undersökning utfördes under slutet av augusti, början av september 2018. Insamlade data analyserades, bearbetades och modellerades senare i Maxwell med hjälp av Leroi, en insticksmodul från CSIRO. Tre separata modeller togs fram med respektive, en, två, och tre plattor. Resultatet jämfördes mot befintliga VTEM-, och resistivitetsmodeller.
Schmidt, Armin R. "Visualisation of multi-source archaeological geophysics data." Rome: Fondazione Ing. Carlo M. Lerici, 2002. http://hdl.handle.net/10454/3281.
Full textFlocco, Daniela. "The geophysics of Antarctic coastal polynyas." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613014.
Full textMorse, David L. "Glacier geophysics at Taylor Dome, Antarctica /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/6801.
Full textLinde, Niklas. "Characterization of Hydrogeological Media Using Electromagnetic Geophysics." Doctoral thesis, Uppsala universitet, Geofysik, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5912.
Full textCox, James. "Baker Wood creosoting site investigation using geophysics /." Connect to resource, 1999. http://hdl.handle.net/1811/28563.
Full textSaunders, Jonathan Howard. "Electrical inversion and characterisation methods in geophysics." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413721.
Full textRio, Joao Filipe Meneses Espinheira. "Advances in laboratory geophysics using bender elements." Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1348997/.
Full textAl-Gezeri, Salem Mohammed. "Modelling of multivariate data in archaeological geophysics." Thesis, University of Leeds, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427765.
Full textVichabian, Yervant. "An environment application of self-potential geophysics." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/46086.
Full textPierce, Christian William. "Three-dimensional geophysics and visualisation in archaeology." Thesis, University of Cambridge, 2000. https://www.repository.cam.ac.uk/handle/1810/272182.
Full textCostall, Alexander Ross. "Hydro-geophysics in High-Quality Coastal Aquifers." Thesis, Curtin University, 2020. http://hdl.handle.net/20.500.11937/82107.
Full textWarino, Charles T. "Resistivity and Radar Images of Collapse Features Attributed to a Previously Undocumented Shallow Coal Mine in Summit County, Ohio." University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1225717244.
Full textUnterborn, Cayman Thomas. "Before Biology: Geologic Habitability and Setting the Chemical and Physical Foundations for Life." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461193916.
Full textVeire, Helene Hafslund. "Combined Inversion of PP and PS Seismic Data for Static and Dynamic Reservoir Characterization." Doctoral thesis, Norwegian University of Science and Technology, Norwegian University of Science and Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-564.
Full textReservoir properties are mainly determined based on well log information. However, wells in most reservoirs are sparse and widely spread compared to the size of the reservoir. Seismic data is thus one of the most important complementary sources of information used to build 3D models of hydrocarbon reservoirs. The need for a high quality reservoir description starts as soon as a discovery is made. In the appraisal phase, hydrocarbons in place and the amount of recoverable reserves are estimated based on the reservoir model. Improved structural models are also needed in optimal well placement during the production and development phase of a reservoir. Knowledge about saturation and pressure distributions in a reservoir are valuable both in the exploration and development phase of a reservoir. This knowledge is used to evaluate the size of a field, determine an optimal drainage pattern, and decide on optimal well design to reduce risks for blow-outs and damage on production equipment. Reducing uncertainty in reservoir property estimates from seismic data have large economic impact on the development of a hydrocarbon reservoir.
Quantitative reservoir property information can be obtained either through direct estimates of reservoir properties from seismic data or through estimates of elastic properties (velocities and densities) that are related to reservoir properties. The relationship between physical properties of rocks and fluids and P-wave seismic data are often empirical and non-unique. This leads to large uncertainties in reservoir models derived from pressure wave seismic data alone. Since shear waves do not propagate through fluids, combined use of pressure wave seismic data and shear wave seismic data might increase our ability to derive fluid and lithology properties from seismic data. One way to obtain information about shear wave velocities over a large area is to acquire multicomponent seismic data (for instance x, y, and z component geophone data). Parts of this thesis focus on methods to combine the information from multicomponent seismic data with pressure wave (hydrophone) seismic data. In this way we improve the accuracy in the estimates of pressure wave velocity, shear wave velocity and density in the subsurface.
To obtain information about changes in reservoir parameters like fluid saturation and pore pressure during production, comparisons between different vintages of seismic data acquired over the field can be performed. Differences in the seismic signal from the same area over a time period (time-lapse seismic data) can be interpreted as changes in reservoir properties. Benefits of improved reservoir characterization include ability to locate bypassed oil and mapping of fluid fronts. This leads to saved costs due to reduced number of misplaced wells, and increased production because of optimized well placement. In the early days of seismic reservoir monitoring, the analyses were qualitative, e.g. to identify undrained areas, analyzing the sealing capacity of faults, and detect drainage patterns. Today, time-lapse seismic analysis is still mainly qualitative. To be able to obtain more quantitative estimates of changes in reservoir properties from the time-lapse seismic data, we need to establish links between the rock parameters and the seismic data. I have used both time-lapse surface seismic data and time-lapse multicomponent seismic data to estimate production related changes in fluid saturation and pressure.
Finally, to be able to utilize rock physical information obtained from seismic reservoir characterization in reservoir modelling, information about uncertainties in the estimates are essential. One way to do this is to use deterministic models (rock physics models) that relates reservoir properties to seismic data, and assume that the model parameters are independent. However, the variables in these estimations are inherently dependent and should be treated as such. By formulating the problem in a Bayesian framework, dependencies between the different variables and spatial dependencies can easily be included. I have used both deterministic uncertainty analysis and Bayesian estimation methods to quantify uncertainties in the estimates.
Yan, Fangzhou. "Application of Time-Frequency Analysis to Characterize Gas Shadows from the Clinton interval in Ohio Seismic Reflection Data." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1484039877315876.
Full textFourie, Christoffel Johannes Stephanus. "In-situ subsurface density estimations using a seismic technique." Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-01162009-110629/.
Full textOrtega, Gelabert Olga. "Advanced numerical techniques for inverse problems in geophysics." Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/670631.
Full textAquesta tesi introdueix una metodologia eficient per acoblar tècniques de Reducció d’Ordre del Model dins el marc de problemes d’inversió probabilística en geofísica. Disposar de models precisos sobre la interacció entre els processos interns de la Terra i les característiques superficials és essencial per tal de fer prediccions fiables dels observables, ja que aquests són una part fonamental de la inferència Bayesiana. Els mètodes de Markov Chain Monte Carlo (MCMC) s’han convertit en un estàndard per tractar amb inversions probabilístiques i es basen en estratègies de mostreig que requereixen solucionar molts problemes directes moltes vegades. L’elevat cost computacional dels problemes directes a gran escala és el principal coll d’ampolla que pot limitar les capacitats i potencial de les inversions probabilístiques multi-observables en geofísica. En concret, els efectes dinàmics provinents del flux del mantell sub-litosfèric no es solen tenir en compte per a l’estimació de l’elevació de la superfície degut a l’elevat cost computacional derivat de resoldre el problema associat de flux de Stokes en 3D. La idea principal d’aquesta tesi es fer servir el mètode de la Base Reduida (RB) com a substitut del problema directe real (flux 3D Stokes) per tal d’obtenir aproximacions ràpides i precises. El substitut es fa servir per generar mostres de la distribució posterior amb un cost computacional molt inferior. Les estratègies RB es basen en expressar la solució d’un problema en un espai de baixa dimensió, i.e. una base reduïda. Aprofitant la naturalesa convergent del MCMC, proposem una estratègia “greedy” que construeix la base sobre la marxa i segons ho requereixi el problema invers. D’aquesta forma, la base està feta a mida per adaptar-se a les característiques posteriors del problema. A més, per tal de garantir la precisió del substitut, definim un estimador d’error “goal-oriented” que es centra en una Quantitat d’Interès específica del problema i, per tant, guia a la base per tal d’aconseguir la precisió necessària en aquelles característiques en particular. Tot això es tradueix en una base adaptada al problema que es més compacta i petita que si hagués de ser precisa en tot el domini. A més, per tal d’afrontar el car assemblatge de les matrius, utilitzem la parametrització del problema i l’estratègia de mostreig per definir una estratègia d’assemblatge que actualitza eficientment les matrius només amb la contribució d’aquells elements que han canviat entre passos successius de la inversió. Els beneficis i limitacions del mètode s’il·lustren a traves de varis exemples numèrics. Finalment, per demostrar l’aplicabilitat del mètode, es presenten dues inversions de problemes més realistes. El primer fa servir la topografia dinàmica per a obtenir la profunditat del límit Litosfera-Astenosfera en un domini esfèric que representa una part de la Terra i el segon s’aplica a un problema més gran en que l’estructura litosfèrica d’Àfrica està discretitzada en 1225 paràmetres.
Shaw, Harold, and Francis A. Lawrence. "AIR FORCE GEOPHYSICS LABORATORY PORTABLE PCM GROUND STATION." International Foundation for Telemetering, 1985. http://hdl.handle.net/10150/615726.
Full textIn early 1981, the Physical Science Laboratory (PSL) was tasked by the Air Force Geophysics Laboratory (AFGL) to develop a portable Pulse-Code Modulation (PCM) telemetry station that would acquire and support the higher PCM data rates from Ariestype rocket payloads. The station would have to provide real-time and near real-time calibration, prelaunch and launch test support to AFGL researchers involved in space vehicle probe analysis. The station would also have to utilize a flexible software system, transportable hardware, and be easily expanded to meet the continually growing and varied needs of the researchers.
Abaunza, Víctor Eduardo Martínez. "Performance optimization of geophysics stencils on HPC architectures." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/183165.
Full textWave modeling is a crucial tool in geophysics, for efficient strong motion analysis, risk mitigation and oil & gas exploration. Due to its simplicity and numerical efficiency, the finite-difference method is one of the standard techniques implemented to solve the wave propagation equations. This kind of applications is known as stencils because they consist in a pattern that replicates the same computation on a multi-dimensional domain. High Performance Computing is required to solve this class of problems, as a consequence of a large number of grid points involved in three-dimensional simulations of the underground. The performance optimization of stencil computations is a challenge and strongly depends on the underlying architecture. In this context, this work was directed toward a twofold aim. Firstly, we have led our research on multicore architectures and we have analyzed the standard OpenMP implementation of numerical kernels from the 3D heat transfer model (a 7-point Jacobi stencil) and the Ondes3D code (a full-fledged application developed by the French Geological Survey). We have considered two well-known implementations (naïve, and space blocking) to find correlations between parameters from the input configuration at runtime and the computing performance; thus, we have proposed a Machine Learning-based approach to evaluate, to predict, and to improve the performance of these stencil models on the underlying architecture. We have also used an acoustic wave propagation model provided by the Petrobras company and we have predicted the performance with high accuracy on multicore architectures. Secondly, we have oriented our research on heterogeneous architectures, we have analyzed the standard implementation for seismic wave propagation model in CUDA, to find which factors affect the performance; then, we have proposed a task-based implementation to improve the performance, according to the runtime configuration set (scheduling algorithm, size, and number of tasks), and we have compared the performance obtained with the classical CPU or GPU only versions with the results obtained on heterogeneous architectures.
DIAZ, DE ALBA PATRICIA. "Numerical treatment for inverse problems in applied Geophysics." Doctoral thesis, Università degli Studi di Cagliari, 2017. http://hdl.handle.net/11584/249578.
Full textGigandet, Katherine M. "Processing and Interpretation of Illinois Basin Seismic Reflection Data." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1401309913.
Full textLevik, Odd Ivar. "Thermophysical and compositional properties of natural gas hydrate." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2000. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-510.
Full textThermophysical properties (dissociation enthalpy, heat capacity, metastability) and compositional properties (hydrate number, free water and fractionation) of natural gas hydrate were studied experimentally on samples that contained large amounts of ice. Methods for continuous hydrate production and sampling, and for quantification of the properties were developed. Hydrate was produced from a natural gas of ethane (5 %mol) and propane (3 %mol) in methane.
A low temperature scanning calorimetry method was developed to measure dissociation enthalpy, heat capacity, hydrate number and free water (ice). During the analysis, the hydrate samples were pressurized to 1.7 MPa with methane and the system operated between the hydrate equilibrium curves of methane and the hydrate forming natural gas. A sample conditioning procedure eliminated thermal effects of desorption as the ice melted. Desorption occurred since the samples were produced and refrigerated to 255 K under a natural gas pressure of 6-10 MPa, but were analyzed and melted under a methane pressure of 1.7 MPa.
A low temperature isothermal calorimetry method was developed to quantify the metastability properties. Metastability was confirmed for temperatures up to 268 K and quantified in terms of the low dissociation rate.
Fractionation data were obtained in the range 3.0 to 7.5 MPa and for subcoolings between 2 and 16 K. High pressure and large subcooling is desirable to suppress fractionation. A fractionation model was proposed. The model coincides with the van der Waals-Platteeuw model for zero subcooling. No fractionation is assumed for hypothetical hydrate formation at infinite driving force (subcooling). Between these two extremes an exponential term was used to describe the fractionation. The model predicted fractionation with an accuracy of about 1%abs corresponding to 1-10%rel.
Gonsiewski, James P. "Bedrock Mapping Using Shear Wave Velocity Characterization and H/V Analysis." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1453247272.
Full textPeterman, David Joseph. "Seismic Reflection Profiling near Middletown, Ohio and Interpretation of Precambrian Deformational Settings." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1463936515.
Full textLewis, Gregory. "The scale invariant generator technique and scaling anisotropy in geophysics /." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68198.
Full textUsing a two-dimensional representation of the linear approximation to GSI, a new, greatly improved, technique for quantifying anisotropic scale invariance in geophysical fields is developed: the Scale Invariant Generator technique (SIG).
The ability of the technique to yield valid estimates is tested by performing the analysis on multifractal (scale invariant) simulations. It was found that SIG yields reasonable estimates for fields with a diversity of anisotropic and statistical characteristics. The analysis is also performed on three satellite cloud radiances and three sea ice SAR reflectivities to test the applicability of the technique. SIG also produced reasonable estimates in these cases.
Seiler, Christina. "Structural and thermal evolution of the Gulf Extensional Province in Baja California, Mexico : implications for Neogene rifting and opening of the Gulf of California /." Connect to thesis, 2009. http://repository.unimelb.edu.au/10187/4212.
Full textWedmark, Mats. "A small scale, high resolution magnetic survey at the archaeological site of Birka, Sweden." Thesis, Uppsala universitet, Geofysik, 1999. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-303228.
Full textAnderson, Michael D. "Analysis of Upper Mantle Reflections Beneath the Trans-Uralian and East-Uralian Zones of the Ural Mountains, Russia." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1418482740.
Full textFan, Chengliang. "Extracting P-primary transmission and reflection impulse responses from teleseismic data." [Bloomington, Ind.] : Indiana University, 2005. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3199414.
Full textSource: Dissertation Abstracts International, Volume: 66-11, Section: B, page: 5867. Adviser: Gary L. Pavlis. Title from dissertation home page (viewed Oct. 11, 2006).
Katsev, Sergei. "Pattern formation in geochemical systems." Thesis, University of Ottawa (Canada), 2002. http://hdl.handle.net/10393/6237.
Full textBer, Tomasz Jan. "The geochemistry of shocked and country rocks from the Lake Wanapitei impact structure, Ontario." Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7830.
Full textScott, Ronald Glenn. "The origins of magnetic anomaly lows associated with three impact structures." Thesis, University of Ottawa (Canada), 1996. http://hdl.handle.net/10393/9822.
Full textPacheco, Anna. "Contribution of hyperspectral remote sensing to the estimation of leaf area index in the context of precision agriculture." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26734.
Full textPar, Andrew R. "DC Resistivity Inversion for Structural Information." Thesis, Colorado School of Mines, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10744014.
Full textThe DC resistivity method has been an important tool for mineral exploration for the direct detection of conductive bodies with economic value. It has also been used for the structural mapping of lithology and alteration where boundaries are zones of economic interest and the detection of edges is the primary goal of surveying. Edge preserving inversion has been explored extensively within the context of potential field methods but has seen relatively little attention for the DC resistivity method. The focus of this thesis is to develop and implement methods which employ specific advantages of the DC method to aid the recovery of edges in the earth’s resistivity distribution.
I begin by utilizing sparse a priori geologic knowledge to create a geologic concept of pervasive blocky resistivity. l1 and l0 approximating measures of model values and model gradients are used as a vehicle to inject the a priori knowledge into a regularized inversion. An iterative method is used to solve for the model that minimizes a total objective function using these general measures.
A series of synthetic modelling and inversion scenarios demonstrate the effectiveness of l1 and minimum gradient support regularization to recover boundaries when compared to traditional sum-of-squares regularization. These blocky inversion schemes also exhibit an improved recovery of the resistivity value of distinct bodies. Additionally, I recognize that the various regularization types have different strengths and weaknesses. I exploit this property to create a new composite regularization that combines smooth model and blocky model regularization. This composite regularization exhibits the strengths of both regularization styles and less of the weaknesses.
A case study on field data from the Sabajo gold deposit was performed utilizing this methodology. Sharp lithologic contacts from drillholes informed the creation of a sharp resistivity concept. A blocky inversion was performed to recover a blocky model that was consistent with this concept and compared to the results of a smooth model inversion. Important differences were noted with their economic implications. I observed that the blocky regularized inversion may have recovered better estimates of the conductivity of features and this can greatly aid prioritization of targets for drilling. Finally, the differences between the inversions utilizing diverse regularization styles provided a proxy for model uncertainty.
Miles, Warner Frederick. "An interpretation of high resolution aeromagnetic data over the Manitouwadge greenstone belt, Ontario, Canada." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0005/MQ36726.pdf.
Full textShepley, Karen Anne Bernice. "Regional geophysical modelling and paleo-reconstruction in and around the southern Slave Structural Province." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0020/MQ57172.pdf.
Full textNagarajan, Badrinath. "A numerical study of the 15 December 1992 TOGA COARE mesoscale convective system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0032/NQ64626.pdf.
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