60f Queralt i Capdevila, Pilar [WorldCat Identities]
WorldCat Identities

Queralt i Capdevila, Pilar

Overview
Works: 17 works in 32 publications in 3 languages and 33 library holdings
Roles: Author, Contributor
Publication Timeline
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Most widely held works by Pilar Queralt i Capdevila
Modelització d'estructures bidimensionals per prospecció elèctrica en corrent continu by Pilar Queralt i Capdevila( Book )

4 editions published between 1989 and 2009 in Catalan and held by 4 WorldCat member libraries worldwide

Combining Discrete Element and Process-based sedimentary models: a new tool to model syntectonic sedimentation by Ana Carmona Bardella( Book )

2 editions published between 2016 and 2017 in English and held by 2 WorldCat member libraries worldwide

"In order to understand the current state of the natural rocky environment and its heterogeneity, we require to study the interaction and time evolution of the numerous geological processes that have contributed to the geological reality we observe today. Given this, the thesis presented here concerns itself with numerical modelling of geological processes. The forward numerical model developed during this thesis is able to simulate deformation and sedimentation in one single setting. To do this, the model uses a novel approach that combines a Discrete Element Model (DEM) and a process- based sedimentary model, Simsafadim (SFM) to link both processes, deformation and sedimentation. The discrete element model (DEM) deals with the simulation of deformation in different materials in 2D and 3D. It is primarily used to investigate the propagation and evolution of deformation in the upper crust caused by tectonic movements. Simsafadim (SFM) is a process-based numerical forward model, which simulates subaqueous clastic transport and sedimentation in three dimensions, including processes of carbonate interaction, production, transport and sedimentation. It can model efficiently the distribution of facies and the depositional architectures in a sedimentary basin and it is a powerful tool for the 3D prediction of stratigraphic structures. Merging both codes provides a new tool for geological modelling in which deformation is influenced by the presence of syntectonic sediment dispersal and deposition. In addition, the tectonic processes change the topographic surface, which influences fluid flow, transport and, consequently, sedimentation in the process-based sedimentary model. The interaction of tectonic and sedimentary processes allows us to study the propagation of deformation in the syntectonic materials as well as how these new sediments influence the propagation of deformation in the pretectonic unit. The model is applied in two different cases studies, in order to test the viability of the new model, as well as to achieve new insight in the respective themes treated: 1) First case study: the effect of normal faulting and a relay ramp on sediment dispersal. The model is used to study the sedimentary infill in an extensional basin, specifically related to a relay ramp system. To perform the test study two configurations are designed: with one normal fault, and with two overlapping normal faults linked by a relay ramp. The different results show that the source area location in relation to the available accommodation space plays the major role in the distribution of different sediment types into the basin. Nonetheless, when the source area for water and sediment is defined as regional and parallel to the fault, the grain size distribution obtained by the two overlapping faults linked by a relay ramp have clear asymmetries when compared with the ones obtained by one-fault configurations. Therefore, the different extensional experiments allow us to conclude that the configuration with a relay ramp can play an important role in the distribution of the sediments into the basin. 2) Second case study: The effect of syntectonic sedimentation on fold geometry The numerical is used to investigate the effect of syntectonic sedimentation on fold geometry and specifically related to a delta progradation surrounded by two growing anticlines. To the initial tectonic configuration that reproduces the growth of two faults, two different cases of the sedimentary model are considered: without sediments, and considering syntectonic sedimentation. Summing up, the main results obtained for these experiments conclude that the syntectonic sedimentation is controlling the mechanism of fold growth and the final fold geometry: the left-side fold shows a left-vergent asymmetric anticline. Moreover, the strain suggests that this anticline is passing from a detachment fold (without sediments) to a fault propagation fold basinwards (with sediments). As a consequence, the inner syncline and the related sedimentary basin are also changing in transversal and longitudinal direction, being wider with syntectonic sedimentation". -- TDX
Anàlisi temps-freqüència de l'estat de polarització del senyal magnetotel·lúric by Magdalena Escalas Oliver( )

2 editions published between 2015 and 2016 in Catalan and held by 2 WorldCat member libraries worldwide

El mètode magnetotel·lúric (MT) és una tècnica geofísica que proporciona la distribució de la resistivitat elèctrica en el subsòl a partir de les fluctuacions temporals del senyal electromagnètic (EM) natural mesurades a la superfície terrestre. El senyal MT sovint esdevé contaminat per soroll EM d'origen antropogènic (soroll cultural). La seva detecció i eliminació és un dels reptes actuals per millorar la qualitat de les respostes obtingudes amb el mètode MT. L'estudi de les característiques del senyal MT i del soroll cultural és un pas clau per poder diferenciar ambdós senyals i eliminar posteriorment el soroll. En general el senyal MT no presenta un estat de polarització concret en el domini temps-freqüència (t-f), ara bé, algunes de les seves fonts naturals com les pulsacions geomagnètiques del tipus Pc3 o les ressonàncies Schumann es caracteritzen pel seu estat de polarització. En canvi, el soroll cultural sol estar polaritzat linealment en una direcció determinada a causa de la posició fixa de les seves fonts a l'espai. Tenint en compte que l'estat de polarització del senyal MT està estretament lligat a les característiques de les seves fonts, en aquesta tesi es proposa la seva anàlisi com a eina per identificar i caracteritzar algunes de les seves fonts naturals i les fonts de soroll cultural que el contaminen. Atès que tant el senyal MT com el soroll cultural són senyals variables amb el temps i presenten múltiples freqüències, s'ha considerat adient analitzar el seu estat de polarització en el domini temps-freqüència (t-f). La principal contribució d'aquesta tesi és el desenvolupament, per primer cop, d'un mètode per analitzar l'estat de polarització del senyal MT en el domini (t-f) a partir de les sèries temporals dels camps elèctric i magnètic. S'han establert les bases teòriques del mètode, que permet obtenir els atributs de polarització d'ambdós camps en el domini (t-f) mitjançant la transformada wavelet, i s'ha implementat en un codi anomenat MTWAVELETS. El mètode desenvolupat s'ha aplicat a l'anàlisi de nombroses sèries temporals MT mesurades a diferents localitzacions i que presenten o bé indicis de soroll cultural o bé indicis de la presència de senyals geomagnètics amb un estat de polarització determinat. A partir de l'anàlisi de sèries temporals MT mesurades a Hontomín (Espanya) i a Lamezia Terme (Itàlia) s'ha detectat el soroll cultural creat per línies elèctriques, la circulació de trens per vies fèrries electrificades amb corrent continu, aerogeneradors i entorns industrials i urbans, i s'ha determinat la posició relativa d'aquestes fonts respecte els punts de mesura. S'ha caracteritzat el comportament que presenten l'amplitud i els atributs de polarització d'aquests senyals sorollosos en el domini (t-f), de manera que a partir d'ara pot identificar-se fàcilment la presència d'aquestes fonts contaminants a sèries temporals MT. D'altra banda, l'anàlisi de dades mesurades a Tramutola (Itàlia) ha suggerit que les pulsacions geomagnètiques del tipus Pc3 són una de les causes de l'oscil·lació que presenten les respostes MT en aquest site en el domini (t-f). Així mateix, s'han detectat i analitzat els quatre primers modes de les ressonàncies Schumann a partir de sèries temporals MT mesurades a Huidobro (Espanya). L'anàlisi (t-f) dels seus atributs de polarització ha permès diferenciar aquest senyals geomagnètics de la resta del senyal MT. La nova eina desenvolupada en aquesta tesi constitueix una aportació significativa per a l'anàlisi del senyal MT, ja que permet detectar i caracteritzar les seves fonts, ja siguin naturals o de soroll. Té nombroses aplicacions: en l'àmbit de la millora de les respostes MT per a la identificació del soroll cultural i de senyals geomagnètics que puguin alterar-les, i en l'estudi de la ionosfera i la magnetosfera per a la caracterització de senyals geomagnètics
The structure and formation of the Tyrrhenian basin in the Western Mediterranean back-arc setting = Formación y estructura de la cuenca del Tirreno en el contexto de retrarco del Mediterráneo Occidental by Manuel Prada Dacasa( Book )

2 editions published between 2013 and 2014 in English and held by 2 WorldCat member libraries worldwide

In this thesis I present a geophysical study that aims to define the structure and petrological nature of the main geological domains in the Central Tyrrhenian basin, and to investigate the mechanisms involved in their formation. The geophysical data used in this thesis was acquired during the MEDOC (2010) survey within the framework of the MEDOC project, which was designed to improve our understanding of the origin and evolution of rifted margins. The present work is based on the analysis, processing, modeling, and interpretation of coincident Wide-Angle Seismic (WAS), Multichannel Seismic (MCS), and gravity data corresponding to the two longest transects acquired during the MEDOC survey in the Central Tyrrhenian basin, the southern Line GH/MEDOC-6 (̃450 km) and the northern Line EF/MEDOC-4 (̃400 km). Both lines run across the Central Tyrrhenian basin from Sardinia to the Campania margin. The processing of MCS data provides the tectonic structure and geometry of the sedimentary basins, whereas the modeling of WAS data from travel-time tomography provides 2D seismic velocity models from which the velocity distribution of the crust and uppermost mantle, and the geometry of the crust-mantle boundary are inferred. The WAS models are then converted to density models using existing empirical relationships for different lithologies in order to test which of the different hypothesis concerning the petrological nature of the basement (e.g. continental/oceanic crust or exhumed mantle) explain better the observed gravity data. The results obtained together with the integration of geological data from rock sampling of the seabed reveals the existence of three geological domains in the Central Tyrrhenian, that is: continental crust, magmatic crust, and exhumed mantle. The comparison between the results of Line EF/MEDOC-4 (northern line) with those of the Line GH/MEDOC-6 (southern line) reveals that the velocity and tectonic structure of the three geological domains differ in some regions from north to south. These differences are most likely attributed to the southward increase of extension that characterizes the Tyrrhenian basin. The basement configuration presented in this thesis led to a completely new definition of geological domains in the Central Tyrrhenian. According to the presented distribution of the basement, rifting in the Central Tyrrhenian basin would have started with continental crust extension, continued with back-arc spreading leading to generation of magmatic back-arc crust, and followed by mantle exhumation intruded by later magmatic episodes. The interpretation of these results differ from current conceptual models of the formation of rifting systems involving mantle exhumation and indicate that the response of the continental lithosphere to extension processes may be more complex than previously assumed. Finally, to explain the mechanism involved in the formation of these domains, I examine the modes of back-arc basin formation proposed to explain the formation of the western Pacific basins [Martinez et al., 2007; Dunn and Martinez, 2011], as well as the causes that may have led to mantle exhumation [Pérez-Gussinyé, et al., 2006]. In summary, the proposed conceptual model is based on a slab rollback and depleted mantle setting, in which production of extension-related melting is limited, thus, crustal accretion is attributed to hydrous flux melting. The model presents 5 stages of opening that includes: (I) a normal subduction scenario followed by (II) development of the back-arc rift, (III) initiation of back-arc spreading, (IV) mantle exhumation, and finally (V) emplacement of large volcanic edifices in the central parts of the basin
CSEM monitoring at the Hontomín CO2 storage site : modeling, experimental design and baseline results by Eloi Vilamajó Llobera( Book )

2 editions published between 2016 and 2017 in English and held by 2 WorldCat member libraries worldwide

"This thesis is devoted to the development of a land-based controlled-source electromagnetics (CSEM) experimental methodology to be applied to the monitoring of CO2 storage at the Technological Development Plant (TDP) of Hontomín (Burgos, Spain). The main objectives of the thesis are 1) the evaluation of the feasibility of performing a CSEM monitoring at Hontomín, 2) the design of the CSEM monitoring experiment, and 3) the acquisition of the baseline (pre-injection) data set and the processing of the data obtaining the geoelectrical response of the structure. A modeling experiment has been performed simulating the resistivity changes in the reservoir caused by the storage and evaluating the ability of the method to detect them. The study analyzes the capabilities of different experimental configurations (source/receiver location and relative orientation, emission frequencies...) in order to decide the appropriate configuration in views of the real experiment. The study considered the simulation of an experimental configuration in two different moments of the storage process (pre- and post-injection). It compares the synthetic results obtained in each case and seeks the differences to infer the presence of CO2. A wide range of scenarios of increasing complexity were simulated, from 1D models with an infinite CO2 plume to models with a 3D plume in a medium that contains the casings of the injection and monitoring wells and considers the noise conditions at the Hontomín TDP. The CO2 effect on the synthetic data was analyzed with two different approaches: quantifying the signal caused by the CO2 on the data, TLS (time-lapse signal), and comparing it with the noise conditions in the study area, D (detectability). A borehole-to-surface configuration is sensitive to the presence of CO2, to its saturation and to the relative position source/plume. Furthermore, it was observed that the steel casings installed in the injection and monitoring wells affect the EM propagation from the transmitter to the surface. The study concluded that the CSEM monitoring is suitable at Hontomín given that measurable changes will occur between time- lapsed data sets. Considering the results obtained in the modeling study, the CSEM monitoring experiment was designed. The baseline acquisition was carried out between April 21st and 26th 2014. A borehole-to-surface configuration was used with three different transmitter dipoles: 1) vertical dipole in the injection well HI (dVED-1), 2) vertical dipole in the monitoring well HA dVED- 2), and 3) horizontal dipole using one electrode in each well (dHED). Receivers were distributed at the surface in two different patterns: cross-shape and circular-shape. During each emission, 86 surface dipoles were measuring the electric field. Data processing focused on the obtaining of the geoelectrical response of the subsurface for each source/receiver configuration and for each processed frequency. To this goal, time series were divided into segments and, for each one, the transfer function between source transmission and receiver electric field were calculated. Experimental data were analyzed in terms of experimental uncertainty (error associated to each measurement) and experimental repeatability. Experimental results allowed to characterize the geoelectrical response of the Hontomín structure (including steel casings). Baseline data quality is high: experimental errors are lower than 1% in amplitude and 1º in phase for most of the data points. Repeatability is high (differences lower than 1% in most of the cases). The casing influence over the experimental data was investigated. We tested the hypothesis that a current was induced along the casing of the injection well. To reproduce the experimental behavior of the data, a number of scenarios have been simulated. For low frequencies, the hypothesis can explain the experimental data. Considering the high data quality obtained and the results of the modeling study, we consider that the CSEM experiment will be able to detect the CO2-caused resistivity changes in the reservoir after the post-injection repetition of the experiment." -- TDX
Magnetotelluric Investigation of Geoelectrical Dimensionality and Study of the Central Betic Crustal Structure, A by Anna Martí i Castells( Book )

2 editions published between 2006 and 2007 in English and held by 2 WorldCat member libraries worldwide

Seismic oceanography a new tool to characterize physical oceanographic structures and processes by Grant George Buffett( Book )

2 editions published between 2010 and 2011 in English and held by 2 WorldCat member libraries worldwide

Joint interpretation of magnetotelluric, seismic, and well-log data in Hontomín (Spain) by Xènia Ogaya( )

1 edition published in 2016 in English and held by 2 WorldCat member libraries worldwide

Two-dimensional modeling and inversion of the controlled-source electromagnetic and magnetotelluric methods using finite elements and full-space PDE-constrained optimization strategies by Savitri Galiana Blanch( Book )

2 editions published in 2016 in English and held by 2 WorldCat member libraries worldwide

"The controlled-source electromagnetics (CSEM) and magnetotellurics (MT) methods arecommon geophysical tools for imaging the electrical properties of the Earth's subsurfaceand are employed independently, jointly, and in combination with other geophysical tech-niques. In order to appreciate measured data, both methods require forward and inversemodeling of the electrically conductive subsurface with the ultimate goal of finding a fea-sible model for which the simulated data reasonably fits the observations. Naturally, thepotential goodness of this fit not only depends on the error in the measured data and on thenumerical error but also on the degree of physical approximation inferred by numericalmodeling. Therefore, active research focuses on new methods for modeling and inversionto obtain accurate and reliable models of the Earth's structure in increasingly complexscenarios. A first step is to enhance modeling approximations by taking into account physical fac-tors such as anisotropy, topography or realistic sources. Second, in order to accommodatethese factors in a modeling and inversion program and to deal with typically large datasets, numerical methods need to be assessed in terms of solution accuracy, time efficiencyand memory demand. The finite elements (FE) modeling methods are known to offer mostflexibility in model geometry and contain quality control mechanisms for the solution, likeshape function order and adaptive mesh refinement. Most emerging modeling programsare based on FE, appreciating significant advantages, but nearly all inverse modeling pro-grams to date are still based on finite differences (FD) or integral equation (IE) methods. Furthermore, inverse modeling developed for electromagnetic (EM) data is generallybased on gradient methods and is formulated in a reduced space, where the only optimiza-tion variables are the model parameters, that is the electric conductivity of the subsurface. Originally, the inverse problem is stated for the EM fields and the conductivity parameter, and constrained by partial differential equations (PDEs) governing the EM field variables. The reduced-space strategy eliminates the field variables by applying equality constraintsand solving then, the unconstrained problem in the reduced-space of model parameters. Acommon drawback of such methods is the repeated costly computation of the solution ofthe forward problem and of the Jacobian matrix of sensitivities (for Newton's based meth-ods). In contrast, it is also possible to solve the inverse problem in the full-space of modelparameters, including both the EM field variables and the electric conductivity parameter. Solving the PDE-constrained optimization problem directly (full-space) has the advantagethat it is only necessary to solve exactly the PDEs at the very end of the optimization provicess but it comes at the cost of many more optimization variables and of the presence ofequality constraints. Also, in particular, within a FE framework, the PDE-constrained op-timization problem provides the additional benefit to include sophisticated FE techniquesin the inversion process, such as adaptive mesh refinement. This thesis develops a robust and versatile adaptive unstructured mesh FE programto numerically model the total field for two-dimensional (2-D) anisotropic CSEM and MTdata, allowing for arbitrarily oriented, three-dimensional (3-D) sources. To represent 3-DCSEM sources for a 2-D physical model, a two-and-a-half-dimensional (2.5-D) approxi-mation is employed. The FE formulations are derived for both methods, for isotropic andanisotropic subsurface conductivity structures. Although the anisotropic case is not general, it includes vertical and dipping anisotropy. The accuracy of the solution is controlledand improved by an adaptive mesh refinement algorithm usinga-posteriorierror estimator methods."--TDX
Magnetotelluric characterisation and monitoring of the Hontomín CO2 storage site, Spain by Xènia Ogaya Garcia( )

2 editions published between 2014 and 2015 in English and held by 2 WorldCat member libraries worldwide

The electromagnetic methods are especially interesting for the characterisation and monitoring of geological storage of CO2 sites. The electrical resistivity is a physical parameter that depends on the mineralogical composition of the rocks, as well as on other characteristics such as porosity, pore connectivity, pore fluid salinity, saturation, temperature and pressure. The CO2 injected in the reservoir produce changes in the resistivity that enables its detection with electromagnetic methods. However, it is necessary to have a thorough knowledge of the structure at the pre-injection state to detect and quantify the changes produced by the injected CO2. The magnetotelluric method is the only electromagnetic method with a penetration depth ranging from ten of metres to hundreds of kilometres depth. Furthermore, this method allows determining the directionality and evolution of the structures in depth thanks to its tensorial character. Hence, the objective of this thesis is to characterise using the magnetotelluric method, the Technological Development Plant (TDP) of Hontomín for Geological Storage of CO2 in a deep saline formation and evaluate the capabilities of the magnetotelluric method to monitor the injected gas. The work presented in this thesis represents an important contribution to the characterisation projects of CO2 storage sites in deep saline formations. The 3D resistivity model obtained defines the reference geoelectrical model for the subsequent electromagnetic monitoring studies. Moreover, the model shows the dome structure of Hontomín and the main fault system. The model allows identifying the potential leakage zones and defines the monitoring needs for the Hontomín TDP. This model also correlates satisfactorily with hydrogeochemical, seismic, gravimetric and well-log data. Additionally, the monitoring capabilities of the magnetotelluric method have been assessed in this work, proposing a new methodology to improve the resolution of the surface magnetotelluric responses to resistivity changes occurred at the reservoir level
Development of a new parallel code for 3-D joint refraction and reflection travel-time tomography of wide-angle seismic data synthetic and real data applications to the study of subduction zones by Adrià Meléndez i Catalán( Book )

2 editions published between 2014 and 2015 in English and held by 2 WorldCat member libraries worldwide

Aquesta tesi està dedicada a la tomografia sísmica. Concretament, he implementat una eina de modelització 3D per a la tomografia conjunta de temps de trajecte de refraccions i reflexions (TOMO3D). La raó darrere d'aquest objectiu és l'evidència de que la informació basada en dades sísmiques 2D no permet copsar la complexitat de gran part dels cossos geològics, i en particular de la zona sismogènica en marges de subducció. El desenvolupament del TOMO3D es basa en el TOMO2D, un codi d'avantguarda per a la tomografia conjunta de refraccions i reflexions en 2D. Els arxius de codi han estat reescrits, redefinint i introduint les funcions necessàries per dur a terme la inversió 3D. Els testos fets amb la versió seqüencial del codi posen de manifest la necessitat de paral·lelització ja que l'increment de la mida dels conjunts de dades així com la modelització de la dimensió espacial afegida fan que les inversions siguin computacionalment exigents. La versió paral·lelitzada del TOMO3D ha sigut aplicada a un cas sintètic complex que simula una zona de subducció. Aquesta primera aplicació 3D serveix per avaluar la correcció de la programació del codi, i com a descripció pas a pas del procediment de modelització. Els resultats demostren la capacitat del codi per recuperar acuradament la distribució de velocitat i la geometria dels dos reflectors. Finalment, el TOMO3D és aplicat a un conjunt 3D de dades de sísmica de gran angle adquirit al marge pacífic d'Equador i Colòmbia per extreure'n un model 3D de la velocitat de les plaques cavalcant i subduïda, que és comparat amb el resultat obtingut amb un codi 3D de tomografia de temps de trajecte de refraccions (FAST). La comparació indica que el TOMO3D és més acurat que el FAST però al mateix temps és computacionalment més exigent. Tot i així, la paral·lelització del TOMO3D permet utilitzar plataformes de supercomputació, a diferència del que passa amb el FAST i la majoria de codis existents
Tomografia elèctrica a escala de laboratori : investigació del sistema roca-salmorra-CO2 by David Bosch Ros( )

2 editions published between 2015 and 2016 in Catalan and held by 2 WorldCat member libraries worldwide

Joint Audio-Magnetotelluric and Passive Seismic Imaging of the Cerdanya Basin by A Gabàs( )

1 edition published in 2016 in English and held by 2 WorldCat member libraries worldwide

Surface geochemical and geophysical studies for geothermal exploration at the southern volcanic rift zone of Tenerife, Canary Islands, Spain( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

Highlights: Soil gas and magnetotelluric surveys were performed in Tenerife Island. The N-S volcanic-rift shows areas of enhanced permeability for deep gas migration. A layer interpreted as the clay cap of the volcano-geothermal system was found. Abstract: A joint geochemistry and magnetotellurics survey was carried out in the southern volcanic rift zone of Tenerife (Canary Islands, Spain) covering an area ∼100 km 2 for geothermal exploration purposes. Soil CO2 and H2 S diffuse effluxes, 222 Rn and 220 Rn activities, soil He, H2, N2, CO2, O2 and H2 S concentrations and isotopic composition of CO2 were measured in 557 selected sampling sites. Magnetotelluric survey (MT) was carried out in the northern part of the study area. A total of 47 MT sites were surveyed and a new 3-D resistivity model was obtained. The observed geochemical anomalies at the soil surface have allowed the detection of areas of deep-seated gas emanations as well as the identification of high vertical permeability volcano-tectonic features in the study area. The resistivity distribution model shows a prominent low-resistivity structure interpreted as a clay alteration cap of variable thickness that might play a role on the mechanism of upward motion of deep-seated gases from the volcano-geothermal system. This is supported by positive correlation between thickness of clay alteration cap and helium emission
Deep crustal electromagnetic structure of Bhuj earthquake region (India) and its implications by K Naganjaneyulu( )

1 edition published in 2010 in Spanish and held by 1 WorldCat member library worldwide

La Pardo Bazán y el naturalismo : tesina by Pilar Queralt i Capdevila( )

2 editions published in 1960 in Spanish and held by 1 WorldCat member library worldwide

 
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Alternative Names
Pilar Queralt wetenschapper

Queralt Capdevila, Pilar

Queralt, P.

Queralt, P. (Pilar)

Queralt, Pilar

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