Готові списки джерел за темами / Magnetotelluric inversion

Добірка наукової літератури з теми "Magnetotelluric inversion"

Автор: Grafiati
Опубліковано: 10 грудня 2022
Оновлено: 29 січня 2023

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Зміст

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Magnetotelluric inversion".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "Magnetotelluric inversion"

1

Matsuno, Tetsuo, Alan D. Chave, Alan G. Jones, Mark R. Muller, and Rob L. Evans. "Robust magnetotelluric inversion." Geophysical Journal International 196, no. 3 (January 2, 2014): 1365–74. http://dx.doi.org/10.1093/gji/ggt484.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Schaa, Ralf, Brett Harris, and Andrew Pethick. "Magnetotelluric inversion strategies." ASEG Extended Abstracts 2019, no. 1 (November 11, 2019): 1–6. http://dx.doi.org/10.1080/22020586.2019.12073167.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Liao, Chen, Xiangyun Hu, Shihui Zhang, Xuewen Li, Quanzeng Yin, Zhao Zhang, and Longfei Zhang. "Joint inversion of gravity, magnetotelluric and seismic data using the alternating direction method of multipliers." Geophysical Journal International 229, no. 1 (November 11, 2021): 203–18. http://dx.doi.org/10.1093/gji/ggab463.

Повний текст джерела
Анотація:
SUMMARY Joint inversion for the same or different geophysical parameters is proved to be an effective technique for obtaining high-resolution solutions. Thus, comprehensive geophysical interpretation based on joint inversion has been widely concerned and applied in recent years. To realize joint inversion conveniently and efficiently, we proposed a new inversion strategy based on the alternating direction method of multipliers. In this regard, three optimization algorithms were presented respectively to attain the joint inversion of body wave traveltime and surface wave dispersion data, to obtain the joint inversion of magnetotelluric and seismic data with cross-gradient constraints, and to acquire gravity constrained inversion. A complex model with inconsistent structures in terms of resistivity, velocity and density was designed to evaluate the accuracy and effectiveness of the multiparameter joint inversion algorithms. In our joint inversion processes, each method was optimized independently and the jointly inverted results were significantly more accurate than those of separate inversions. Finally, we applied the algorithms to the field data involving gravity anomaly data, magnetotelluric data and Rayleigh wave dispersion data. The reliable underground structure was achieved by the joint interpretation of density, resistivity and velocity profiles, which verified the practicality of the inversion strategy in the actual data.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Srnka, L. J., and W. Y. CrutchfieldII. "Riccati inversion of magnetotelluric data." Geophysical Journal International 91, no. 1 (October 1987): 211–28. http://dx.doi.org/10.1111/j.1365-246x.1987.tb05221.x.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Smith, J. Torquil, and John R. Booker. "Magnetotelluric inversion for minimum structure." GEOPHYSICS 53, no. 12 (December 1988): 1565–76. http://dx.doi.org/10.1190/1.1442438.

Повний текст джерела
Анотація:
Structure can be measured in terms of a norm of the derivative of a model with respect to a function of depth f(z), where the model m(z) is either the conductivity σ or log σ. An iterative linearized algorithm can find models that minimize norms of this form for chosen levels of chi‐squared misfit. The models found may very well be global minima of these norms, since they are not observed to depend on the starting model. Overfitting data causes extraneous structure. Some choices of the depth function result in systematic overfitting of high frequencies, a “blue” fit, and extraneous shallow structure. Others result in systematic overfitting of low frequencies, a “red” fit, and extraneous deep structure. A robust statistic is used to test for whiteness; the fit can be made acceptably white by varying the depth function f(z) which defines the norm. An optimum norm produces an inversion which does not introduce false structure and which approaches the true structure in a reasonable way as data errors decrease. Linearization errors are often so small that models of σ (but not log σ) may be reasonably interpreted as the true conductivity averaged through known resolution functions.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Bawahab, Nabil, Udi Harmoko, Tony Yulianto, and Irvan Ramadhan. "Identification of low resistivity layers in the “N” geothermal field using 2D magnetotelluric inversion modelling." Journal of Physics and Its Applications 2, no. 2 (May 11, 2020): 85–89. http://dx.doi.org/10.14710/jpa.v2i2.7532.

Повний текст джерела
Анотація:
Magnetotelluric research in the “N” geothermal field has been carried out to see the subsurface detail in the “N” geothermal field. 2D inversion model is generated by secondary data from magnetotelluric data collection in the form of time series data to become 2D models. Magnetotellurics method is used to identify geothermal system components, especially identifying layers with low resistivity values (2 Ω.m - 10 Ω.m) or also called as the cap rock which is seen with a very contrasting color difference compared to the surrounding layers. There are manifestations on the “N” geothermal field which reinforce the assumption that there is a geothermal system in this area. This research begins by processing time series data to become apparent resistivity and phase data. Time series data processing in this study uses several processing methods to produce better apparent resistivity and phase data. The final result of this study is a 2D model that illustrates the contour of the resistivity value of rocks laterally or vertically. 2D model interpretation in this study identified the cap rock layer with low resistivity distribution (2 Ω.m - 10 Ω.m), the medium resistivity zone identified as the reservoir layer (11 Ω.m - 70 Ω.m), and the resistive zone which has high resistivity value (more than 70 Ω.m).
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Wang, Shunguo, Mehrdad Bastani, Steven Constable, Thomas Kalscheuer, and Alireza Malehmir. "Boat-towed radio-magnetotelluric and controlled source audio-magnetotelluric study to resolve fracture zones at Äspö Hard Rock Laboratory site, Sweden." Geophysical Journal International 218, no. 2 (April 23, 2019): 1008–31. http://dx.doi.org/10.1093/gji/ggz162.

Повний текст джерела
Анотація:
SUMMARY Boat-towed radio-magnetotelluric (RMT) measurements using signals between 14 and 250 kHz have attracted increasing attention in the near-surface applications for shallow water and archipelago areas. A few large-scale underground infrastructure projects, such as the Stockholm bypass in Sweden, are planned to pass underneath such water zones. However, in cases with high water salinity, RMT signals have a penetration depth of a few metres and do not reach the geological structures of interest in the underlying sediments and bedrock. To overcome this problem, controlled source signals at lower frequencies of 1.25 to 12.5 kHz can be utilized to improve the penetration depth and to enhance the resolution for modelling deeper underwater structures. Joint utilization of boat-towed RMT and controlled source audio-magnetotellurics (CSAMT) was tested for the first time at the Äspö Hard Rock Laboratory (HRL) site in south-eastern Sweden to demonstrate acquisition efficiency and improved resolution to model fracture zones along a 600-m long profile. Pronounced galvanic distortion effects observed in 1-D inversion models of the CSAMT data as well as the predominantly 2-D geological structures at this site motivated usage of 2-D inversion. Two standard academic inversion codes, EMILIA and MARE2DEM, were used to invert the RMT and CSAMT data. EMILIA, an object-oriented Gauss–Newton inversion code with modules for 2-D finite difference and 1-D semi-analytical solutions, was used to invert the RMT and CSAMT data separately and jointly under the plane-wave approximation for 2-D models. MARE2DEM, a Gauss–Newton inversion code for controlled source electromagnetic 2.5-D finite element solution, was modified to allow for inversions of RMT and CSAMT data accounting for source effects. Results of EMILIA and MARE2DEM reveal the previously known fracture zones in the models. The 2-D joint inversions of RMT and CSAMT data carried out with EMILIA and MARE2DEM show clear improvement compared with 2-D single inversions, especially in imaging uncertain fracture zones analysed in a previous study. Our results show that boat-towed RMT and CSAMT data acquisition systems can be utilized for detailed 2-D or 3-D surveys to characterize near-surface structures underneath shallow water areas. Potential future applications may include geo-engineering, geohazard investigations and mineral exploration.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Wittke, J., and B. Tezkan. "Two-dimensional meshless modelling and TE-mode inversion of magnetotelluric data." Geophysical Journal International 226, no. 2 (April 14, 2021): 1250–61. http://dx.doi.org/10.1093/gji/ggab147.

Повний текст джерела
Анотація:
SUMMARY We present a new 2-D forward modelling and inversion scheme to interpret magnetotelluric/radio-magnetotelluric data by utilizing a novel meshless forward operator. We use this discretization technique within an inverse scheme to recover conductivity structures from given magnetotelluric data. To approximate solutions of the partial differential equations that describe the magnetotelluric experiment, we discretize the subsurface only in terms of nodes. These node sets, which are simple to generate, are used to derive the differential operators’ approximations in a generalized meshless framework. First, we study and compare forward modelling calculations to an analytical and known solution from the literature. Several example calculations are given, which validate the proposed meshless forward operator. We then formulate our inverse scheme for TE-mode data, which uses only subsets of the nodal subsurface parametrization to generate conductivity structures from this given data. The inverse scheme consists of a Gauss–Newton algorithm combined with the generalized meshless framework. To validate the algorithm, we present inversion results from synthetic and field data. We compare our results to conductivity models calculated by established, well-known inversion schemes and literature results. We report that our algorithm can accurately model magnetotelluric responses and recover meaningful conductivity models, explaining given magnetotelluric data.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Buland, Arild, and Odd Kolbjørnsen. "Bayesian inversion of CSEM and magnetotelluric data." GEOPHYSICS 77, no. 1 (January 2012): E33—E42. http://dx.doi.org/10.1190/geo2010-0298.1.

Повний текст джерела
Анотація:
We have developed a Bayesian methodology for inversion of controlled source electromagnetic (CSEM) data and magnetotelluric (MT) data. The inversion method provided optimal solutions and also the associated uncertainty for any sets of electric and magnetic components and frequencies from CSEM and MT data. The method is based on a 1D forward modeling method for the electromagnetic (EM) response for a plane-layered anisotropic earth model. The inversion method was also designed to invert common midpoint (CMP)-sorted data along a 2D earth profile assuming locally horizontal models in each CMP position. The inversion procedure simulates from the posterior distribution using a Markov chain Monte Carlo (McMC) approach based on the Metropolis-Hastings algorithm. The method that we use integrates available geologic prior knowledge with the information in the electromagnetic data such that the prior model stabilizes and constrains the inversion according to the described knowledge. The synthetic examples demonstrated that inclusion of more data generally improves the inversion results. Compared to inversion of the inline electric component only, inclusion of broadside and magnetic components and an extended set of frequency components moderately decreased the uncertainty of the inversion. The results were strongly dependent on the prior knowledge imposed by the prior distribution. The prior knowledge about the background resistivity model surrounding the target was highly important for a successful and reliable inversion result.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Wiik, Torgeir, Ketil Hokstad, Bjørn Ursin, and Lutz Mütschard. "Joint contrast source inversion of marine magnetotelluric and controlled-source electromagnetic data." GEOPHYSICS 78, no. 6 (November 1, 2013): E315—E327. http://dx.doi.org/10.1190/geo2012-0477.1.

Повний текст джерела
Анотація:
We evaluated a joint contrast source inversion scheme for marine controlled-source electromagnetic (mCSEM) and magnetotelluric (MT) data based on a scattered field formulation. The scheme considered only contrasts in electric conductivity, and it allowed the medium to be transversely isotropic with a vertical symmetry axis. The method was based on the integral equation formulation of electromagnetic field propagation, and we demonstrated how the method solved the inverse problem of determining the conductivity structure of the subsurface. The method did not consider MT impedances as data input to inversion, but instead explicitly the field components, and the consequences of this approach, were discussed. Although there are challenges associated with source estimation and data noise, we found it easier to make connections to CSEM and it simplified some computational issues. Three synthetic examples were considered to demonstrate the method: a reservoir below an anisotropic overburden, a salt diapir, and a reservoir near a salt diapir. MT and CSEM data were first treated sequentially, first inverting the MT data and using the result as the initial model and in the regularization in CSEM inversion. The result of this approach was then compared to a joint inversion. The same approach was finally applied to a real data set. We found that sequential inversions in some situations produced similar results as joint inversions, and hence, joint inversion may not be necessary in all situations. Nonetheless, joint inversion could be useful for imaging salt diapirs and eventually hydrocarbons near salt. In particular, it was useful to map the spatial extent of the salt diapirs. It was, moreover, a useful tool for checking data consistency in different models with respect to several data types.
Стилі APA, Harvard, Vancouver, ISO та ін.
Більше джерел

Дисертації з теми "Magnetotelluric inversion"

1

Chen, Xiaoming. "Two-dimensional constrained anisotropic inversion of magnetotelluric data." Phd thesis, Universität Potsdam, 2012. http://opus.kobv.de/ubp/volltexte/2012/6316/.

Повний текст джерела
Анотація:
Tectonic and geological processes on Earth often result in structural anisotropy of the subsurface, which can be imaged by various geophysical methods. In order to achieve appropriate and realistic Earth models for interpretation, inversion algorithms have to allow for an anisotropic subsurface. Within the framework of this thesis, I analyzed a magnetotelluric (MT) data set taken from the Cape Fold Belt in South Africa. This data set exhibited strong indications for crustal anisotropy, e.g. MT phases out of the expected quadrant, which are beyond of fitting and interpreting with standard isotropic inversion algorithms. To overcome this obstacle, I have developed a two-dimensional inversion method for reconstructing anisotropic electrical conductivity distributions. The MT inverse problem represents in general a non-linear and ill-posed minimization problem with many degrees of freedom: In isotropic case, we have to assign an electrical conductivity value to each cell of a large grid to assimilate the Earth's subsurface, e.g. a grid with 100 x 50 cells results in 5000 unknown model parameters in an isotropic case; in contrast, we have the sixfold in an anisotropic scenario where the single value of electrical conductivity becomes a symmetric, real-valued tensor while the number of the data remains unchanged. In order to successfully invert for anisotropic conductivities and to overcome the non-uniqueness of the solution of the inverse problem it is necessary to use appropriate constraints on the class of allowed models. This becomes even more important as MT data is not equally sensitive to all anisotropic parameters. In this thesis, I have developed an algorithm through which the solution of the anisotropic inversion problem is calculated by minimization of a global penalty functional consisting of three entries: the data misfit, the model roughness constraint and the anisotropy constraint. For comparison, in an isotropic approach only the first two entries are minimized. The newly defined anisotropy term is measured by the sum of the square difference of the principal conductivity values of the model. The basic idea of this constraint is straightforward. If an isotropic model is already adequate to explain the data, there is no need to introduce electrical anisotropy at all. In order to ensure successful inversion, appropriate trade-off parameters, also known as regularization parameters, have to be chosen for the different model constraints. Synthetic tests show that using fixed trade-off parameters usually causes the inversion to end up by either a smooth model with large RMS error or a rough model with small RMS error. Using of a relaxation approach on the regularization parameters after each successful inversion iteration will result in smoother inversion model and a better convergence. This approach seems to be a sophisticated way for the selection of trade-off parameters. In general, the proposed inversion method is adequate for resolving the principal conductivities defined in horizontal plane. Once none of the principal directions of the anisotropic structure is coincided with the predefined strike direction, only the corresponding effective conductivities, which is the projection of the principal conductivities onto the model coordinate axes direction, can be resolved and the information about the rotation angles is lost. In the end the MT data from the Cape Fold Belt in South Africa has been analyzed. The MT data exhibits an area (> 10 km) where MT phases over 90 degrees occur. This part of data cannot be modeled by standard isotropic modeling procedures and hence can not be properly interpreted. The proposed inversion method, however, could not reproduce the anomalous large phases as desired because of losing the information about rotation angles. MT phases outside the first quadrant are usually obtained by different anisotropic anomalies with oblique anisotropy strike. In order to achieve this challenge, the algorithm needs further developments. However, forward modeling studies with the MT data have shown that surface highly conductive heterogeneity in combination with a mid-crustal electrically anisotropic zone are required to fit the data. According to known geological and tectonic information the mid-crustal zone is interpreted as a deep aquifer related to the fractured Table Mountain Group rocks in the Cape Fold Belt.
Tektonische und geologische Prozesse verursachen häufig eine strukturelle Anisotropie des Untergrundes, welche von verschiedenen geophysikalischen Methoden beobachtet werden kann. Zur Erstellung und Interpretation geeigneter, realistischer Modelle der Erde sind Inversionsalgorithmen notwendig, die einen anisotropen Untergrund einbeziehen können. Für die vorliegende Arbeit habe ich einen magnetotellurischen (MT) Datensatz vom Cape Fold Gürtel in Südafrika untersucht. Diese Daten weisen auf eine ausgeprägte Anisotropie der Kruste hin, da z.B. die MT Phasen außerhalb des erwarteten Quadranten liegen und nicht durch standardisierte isotrope Inversionsalgorithmen angepasst und ausgewertet werden können. Um dieses Problem zu beheben, habe ich eine zweidimensionale Inversionsmethode entwickelt, welche eine anisotrope elektrische Leitfähigkeitsverteilungen in den Modellen zulässt. Die MT Inversion ist im allgemeinen ein nichtlineares, schlecht gestelltes Minimierungsproblem mit einer hohen Anzahl an Freiheitsgraden. Im isotropen Fall wird jeder Gitterzelle eines Modells ein elektrischer Leitfähigkeitswert zugewiesen um den Erduntergrund nachzubilden. Ein Modell mit beispielsweise 100 x 50 Zellen besitzt 5000 unbekannte Modellparameter. Im Gegensatz dazu haben wir im anisotropen Fall die sechsfache Anzahl, da hier aus dem einfachen Zahlenwert der elektrischen Leitfähigkeit ein symmetrischer, reellwertiger Tensor wird, wobei die Anzahl der Daten gleich bleibt. Für die erfolgreiche Inversion von anisotropen Leitfähigkeiten und um die Nicht-Eindeutigkeit der Lösung des inversen Problems zu überwinden, ist eine geeignete Einschränkung der möglichen Modelle absolut notwendig. Dies wird umso wichtiger, da die Sensitivität von MT Daten nicht für alle Anisotropieparameter gleich ist. In der vorliegenden Arbeit habe ich einen Algorithmus entwickelt, welcher die Lösung des anisotropen Inversionsproblems unter Minimierung einer globalen Straffunktion berechnet. Diese besteht aus drei Teilen: der Datenanpassung, den Zusatzbedingungen an die Glätte des Modells und die Anisotropie. Im Gegensatz dazu werden beim isotropen Fall nur die ersten zwei Parameter minimiert. Der neu definierte Anisotropieterm wird mit Hilfe der Summe der quadratischen Abweichung der Hauptleitfähigkeitswerte des Modells gemessen. Die grundlegende Idee dieser Zusatzbedingung ist einfach. Falls ein isotropes Modell die Daten ausreichend gut anpassen kann, wird keine elektrische Anisotropie zusätzlich in das Modell eingefügt. Um eine erfolgreiche Inversion zu garantieren müssen geeignete Regularisierungsparameter für die verschiedenen Nebenbedingungen an das Modell gewählt werden. Tests mit synthetischen Modellen zeigen, dass bei festgesetzten Regularisierungsparametern die Inversion meistens entweder in einem glatten Modell mit hohem RMS Fehler oder einem groben Modell mit kleinem RMS Fehler endet. Die Anwendung einer Relaxationsbedingung auf die Regularisierung nach jedem Iterationsschritt resultiert in glatteren Inversionsmodellen und einer höheren Konvergenz und scheint ein ausgereifter Weg zur Wahl der Parameter zu sein. Die vorgestellte Inversionsmethode ist im allgemeinen in der Lage die Hauptleitfähigkeiten in der horizontalen Ebene zu finden. Wenn keine der Hauptrichtungen der Anisotropiestruktur mit der vorgegebenen Streichrichtung übereinstimmt, können nur die dazugehörigen effektiven Leitfähigkeiten, welche die Projektion der Hauptleitfähigkeiten auf die Koordinatenachsen des Modells darstellen, aufgelöst werden. Allerdings gehen die Informationen über die Rotationswinkel verloren. Am Ende meiner Arbeit werden die MT Daten des Cape Fold Gürtels in Südafrika analysiert. Die MT Daten zeigen in einem Abschnitt des Messprofils (> 10 km) Phasen über 90 Grad. Dieser Teil der Daten kann nicht mit herkömmlichen isotropen Modellierungsverfahren angepasst und daher mit diesen auch nicht vollständig ausgewertet werden. Die vorgestellte Inversionsmethode konnte die außergewöhnlich hohen Phasenwerte nicht wie gewünscht im Inversionsergebnis erreichen, was mit dem erwähnten Informationsverlust der Rotationswinkel begründet werden kann. MT Phasen außerhalb des ersten Quadranten können für gewöhnlich bei Anomalien mit geneigter Streichrichtung der Anisotropie gemessen werden. Um diese auch in den Inversionsergebnissen zu erreichen ist eine Weiterentwicklung des Algorithmus notwendig. Vorwärtsmodellierungen des MT Datensatzes haben allerdings gezeigt, dass eine hohe Leitfähigkeitsheterogenität an der Oberfläche in Kombination mit einer Zone elektrischer Anisotropie in der mittleren Kruste notwendig sind um die Daten anzupassen. Aufgrund geologischer und tektonischer Informationen kann diese Zone in der mittleren Kruste als tiefer Aquifer interpretiert werden, der im Zusammenhang mit den zerrütteten Gesteinen der Table Mountain Group des Cape Fold Gürtels steht.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Le, Van Anh Cuong. "Cooperative Inversion of Magnetotelluric and Seismic Data." Thesis, Curtin University, 2017. http://hdl.handle.net/20.500.11937/59652.

Повний текст джерела
Анотація:
Cooperative inversion is the beneficial transference of information from one geophysical technique to another for improving the recovery of subsurface rock properties. The research’s focus is the development and comparison of new strategies for cooperatively inverting seismic and magnetotelluric data. This is intended to improve the recovery of subsurface electrical conductivity. The developed techniques are applied to two industry scale case sites containing large co-located seismic and MT surveys.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Alvarez, Aramberri Julen. "hp-Adaptive Simulation and Inversion of Magnetotelluric Measurements." Thesis, Pau, 2015. http://www.theses.fr/2015PAUU3056/document.

Повний текст джерела
Анотація:
La magnéto-tellurique (MT) (Cagniard 1953, Tikhonov 1950) est une technique d'exploration de la Terre basée sur des mesures de champs électromagnétiques (EM). Une source naturelle (non artificielle) harmonique en temps et située dans l'ionosphère (Weaver 1994) produit un champ EM régi par les équations de Maxwell. Les champs électromagnétiques sont enregistrés par plusieurs récepteurs placés sur la surface de la Terre. Ces mesures sont utilisées pour produire une image du sous-sol à partir d'un procédé d'inversion utilisant des méthodes numériques. Nous utilisons la méthode hp-FEM résultant d'une extension du travail de Demkowicz 2005. Nous avons développé un logiciel qui résout, pour la première fois, le problème MT avec des éléments finis auto-adaptatifs. La méthode hp-FEM permet des raffinements locaux, à la fois en taille h et en ordre p sur les éléments, ce qui est un avantage notoire puisque la combinaison de ces deux types de critères permet de mieux capter la présence de singularités, fournissant ainsi des erreurs de discrétisation faible. C'est donc une méthode très précise dont la convergence est exponentielle (Gui and Babuska 1986, Babuska and Guo 1996). En raison des défis d'implémentation encore non résolus (Demkowicz et al. 2002) et de la complexité technique des calculs hp-FEM en 3D, nous nous limitons, dans ce travail, à des calculs en 1D et 2D.Le domaine de calcul est tronqué par un matériau absorbant (Perfectly Matched Layer PML, Berenger 1994), qui est conçu pour s'adapter automatiquement aux propriétés physiques des matériaux. En particulier, il s'ajuste efficacement à l'interface air-sol, où le contraste entre la conductivité des matériaux atteint jusqu'à seize ordres de grandeur. Dans cette thèse, nous présentons également des résultats préliminaires pour la mise en place d'une technique dimensionnelle adaptative plus connue sous le nom de DAM (Dimensionally Adaptive Method (DAM)). Lorsque la distribution de la résistivité du sous-sol dépend de multiples variables spatiales, une analyse correcte de la dimensionnalité (Ledo 2005, Martí et al. 2009, Weaver and Agarwal 2000) rend parfois possible de considérer les différentes régions avec des dimensions spatiales différentes. Par exemple, il est parfois possible d’interpréter la distribution comme une formation unidimensionnelle plus quelques hétérogénéités en 2D (ou 3D). Basée sur cette interprétation, la DAM tire profit d’une telle situation. Ainsi, l'idée principale de cette méthode est d'effectuer l'adaptativité sur la dimension spatiale en commençant par un problème de faible dimension et en utilisant les résultats obtenus pour minimiser le coût des problèmes de dimension supérieure. Nous commençons l'inversion avec un modèle 1D. Les résultats de ce problème d'inversion 1D sont utilisés comme information a priori sur les modèles de dimension supérieure. Un avantage fondamental de cette approche est que nous pouvons utiliser les solutions des problèmes de dimension inférieure précédemment calculées comme composantes du terme de régularisation associé à un problème de dimension supérieure afin d'augmenter la robustesse de l'inversion. Cette thèse propose également une analyse numérique rigoureuse de divers aspects des problèmes MT. En particulier, nous avons: (a) étudié l'effet de la source, (b) effectué une analyse fréquentielle de sensibilité, (c) illustré l'augmentation du taux de convergence lorsque l'adaptativité hp est employée, (d) séparé les effets 1D et 2D dans la solution numérique et (e) exploré l'intérêt de considérer différentes variables pour effectuer l'inversion
The magnetotelluric (MT) method is a passive exploration technique that aims at estimating the resistivity distribution of the Earth's subsurface, and therefore at providing an image of it. This process is divided into two different steps. The first one consists in recording the data. In a second step, recorded measurements are analyzed by employing numerical methods. This dissertation focuses in this second task. We provide a rigorous mathematical setting in the context of the Finite Element Method (FEM) that helps to understand the MT problem and its inversion process. In order to recover a map of the subsurface based on 2D MT measurements, we employ for the first time in Mts a multi-goal oriented self adaptive hp-Finite Element Method (FEM). We accurately solve both the full formulation as well as a secondary field formulation where the primary field is given by the solution of a 1D layered media. To truncate the computational domain, we design a Perfectly Matched Layer (PML) that automatically adapts to high-contrast material properties that appear within the subsurface and on the air-ground interface. For the inversion process, we develop a first step of a Dimensionally Adaptive Method (DAM) by considering the dimension of the problem as a variable in the inversion. Additionally, this dissertation supplies a rigorous numerical analysis for the forward and inverse problems. Regarding the forward modelization, we perform a frequency sensitivity analysis, we study the effect of the source, the convergence of the hp-adaptivity, or the effect of the PML in the computation of the electromagnetic fields and impedance. As far as the inversion is concerned, we study the impact of the selected variable for the inversion process, the different information that each mode provides,and the gains of the DAM approach
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Zhang, Ai Jun. "Modelling and inversion of two-dimensional magnetotelluric data." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/14717.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Lu, Xinyou. "Inversion of controlled-source audio-frequency magnetotelluric data /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/6799.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Wilhelms, Wenke. "Development of a three-dimensional all-at-once inversion approach for the magnetotelluric method." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2016. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-207548.

Повний текст джерела
Анотація:
A three-dimensional inversion was implemented for magnetotellurics, which is a passive electromagnetic method in geophysics. It exploits natural electromagnetic fields of the Earth, which function as sources. Their interaction with the conductive parts of the subsurface are registered when components of the electric and the magnetic field are measured and evaluated. The all-at-once approach is an inversion scheme that is relatively new to geophysics. In this approach, the objective function – the basis of each inversion – is called the Lagrangian. It consists of three parts: (i) the data residual norm, (ii) the regularisation part, and (iii) the forward problem. The latter is the significant difference to conventional inversion approaches that are built up of a forward calculation part and an inversion part. In the case of all-at-once, the forward problem is incorporated in the objective function and is therefore already taken into account in each inversion iteration. Thus, an explicit forward calculation is obsolete. As an objective function, the Lagrangian shall reach a minimum and therefore its first and second derivatives are evaluated. Hence, the gradient of the Lagrangian and its Hessian are constituent parts of the KKT system – the Newton-type system that is set up in the all-at-once inversion. Conventional inversion approaches avoid the Hessian because it is a large, dense, not positive definite matrix that is challenging to handle. However, it provides additional information to the inversion, which raises hope for a high quality inversion result. As a first step, the inversion was programmed for the more straightforward one-dimensional magnetotelluric case. This was particularly suitable to become familiar with sQMR – a Krylov subspace method which is essential for the three-dimensional case to be able to work with the Hessian and the resulting KKT system. After the implementation and validation of the one-dimensional forward operator, the Lagrangian and its derivatives were set up to complete the inversion, which successfully solved the KKT system. Accordingly, the three-dimensional forward operator also needed to be implemented and validated, which was done using published data from the 3D-2 COMMEMI model. To realise the inversion, the Lagrangian was assembled and its first and second derivatives were validated with a test that exploits the Taylor expansion. Then, the inversion was initially programmed for the Gauss-Newton approximation where second order information is neglected. Since the system matrix of the Gauss-Newton approximation is positive definite, the solution of this system of equations could be carried out by the conventional solver pcg. Based on that, the complete KKT system (Newton\\\'s method) was set up and preconditioned sQMR solved this system of equations.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Ulugergerli, Emin Ugur. "Development and application of 2D magnetotelluric inversion in complex domain." Thesis, University of Leicester, 1998. http://hdl.handle.net/2381/30430.

Повний текст джерела
Анотація:
The magnetotelluric method is widely used in the investigation of the geo-electric structure of the earth. The field data are traditionally inverted to reveal the subsurface structure solved using regularised iterative inversion techniques. These interpretation schemes effect matrix computations in real domain due to operational simplicity. The speed of convergence of these techniques is controlled by the calculation type and the size of the program or more specifically, size of the matrices used. A common problem encountered when dealing with real matrices in 2D regularised inversion is their huge size. To partly overcome this problem, a new inversion strategy using complex singular value decomposition techniques has been successfully developed. The use of analytical partial derivatives and a variety of problem regularization measures ensure that the scheme is stable and rapidly convergent. In this method, instead of using the Cagniard apparent resistivity and phase, the frequency normalised impedance is adopted as the interpretative data functions for improved model resolution. Sample applications to several synthetic and to field data from Parnaiba Basin in Brazil proved successful and are presented in this thesis. It is also found that the complex form of the data-space and parameter-space eigenvectors contain information on parameter resolution. Suggestions are made for further studies especially of methods of improving parameter resolution in 2D inversion.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Shan, Chunling. "Natural and Controlled Source Magnetotelluric Data Processing and Modeling." Doctoral thesis, Uppsala universitet, Geofysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-229917.

Повний текст джерела
Анотація:
In this thesis, four studies using different geophysical electromagnetic methods are presented. In the first study dealing with airborne measurements, the noise response due to the rotation of the aircraft and the aircraft itself as a metallic conductive body on the Earth's electromagnetic response in very low frequency and low frequency band was investigated. The magnetic fields are independent of the aircraft in the VLF band and part of the LF band. But at higher frequencies (above 100 kHz), the signals are more influenced by the aircraft. The aircraft also generates its own noise frequencies which are mixed with the radio transmitter signals. The second and third studies are applications of radio-, controlled source-magnetotellurics and electrical resistivity tomography methods at a quick-clay landslide site in southwest Sweden. The data are processed and modeled in 2D and 3D, and the models are compared with high-resolution seismic and geotechnical data. The obtained results were further validated and refined by performing synthetic tests in the second study. The third study shows that the 3D models provide larger and more continuous volume of the quick clay structure than traditional 2D models. Both studies have shown that integrated application of geophysical methods for landslides is ideal. Quick clays often overlie the coarse-grained layers showing an increase of resistivity values in the models. In the fourth study, a new audio magnetotelluric data acquisition technique is developed and is named moving magnetotellurics (MMT). In this new technique, the magnetic sensors are placed on the ground and only 15 to 20 minutes data are acquired for each station, which usually is enough to cover the frequency range 30-300 Hz. The new technique is more efficient and convenient than the traditional magnetotelluric method, and test measurements have shown that it is an applicable method in shallow depth studies.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Yan, Ping. "Inversion of Magnetotelluric Data Constrained by Borehole Logs and Reflection Seismic Sections." Doctoral thesis, Uppsala universitet, Geofysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-303498.

Повний текст джерела
Анотація:
This thesis presents two new algorithms for doing constrained Magnetotelluric (MT) inversion based on an existing Occam 2D inversion program. The first algorithm includes borehole resistivity logs as prior information to constrain resistivity directly in the vicinity of boreholes. The second algorithm uses reflection seismic data as prior constraints to transfer structural information from seismic images to 2D resistivity models. These two algorithms are efficient (proved through tests of synthetic examples) and widely applicable. In this thesis, they have been successfully applied to the COSC (Collisional Orogeny in the Scandinavian Caledonides) MT data. The COSC project aims to study the mountain belt dynamics in central Sweden by drilling two 2.5 km deep boreholes. MT data were collected to locate the main décollement that separates the overlying Caledonian allochthons and the underlying Precambrian basement, as the main décollement is associated with very conductive Alum shale. The previous interpretation based on part of the COSC seismic profile (CSP) was that the main décollement was located along a reflection with depth of 4.5 km underneath Åre and ~3 km underneath Mörsil, in central Jämtland. The MT resistivity model reveals a very conductive layer in the central and western parts of the profile, the top of which coincides with the first seismic reflection. This means that the first conductive alum shale layer occurs at less than 1 km depth, supporting a new interpretation of the main décollement at shallower depth. In a re-interpretation of the CSP data based on the MT model, the main décollement occurs a few hundred metres below the top of the conductor and is coincident with a laterally continuous seismic reflection. Further, the overlying seismic reflections resemble imbricated alum shale of the Lower Allochthon. MT inversion using seismic constraints from CSP gives further support to the new interpretation. Moreover, MT investigations were conducted in the Alnö alkaline and carbonatite ring-intrusion complex in Sweden. 2D and 3D resistivity models inverted from MT data together with resistivity and porosity laboratory measurements delineate a fossil magma chamber as a resistive anomaly surrounded by electrically conductive up-doming and ring-shaped faults and fractures.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Chen, Xiaoming [Verfasser], and Ute [Akademischer Betreuer] Weckmann. "Two-dimensional constrained anisotropic inversion of magnetotelluric data / Xiaoming Chen. Betreuer: Ute Weckmann." Potsdam : Universitätsbibliothek der Universität Potsdam, 2012. http://d-nb.info/1029243824/34.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Більше джерел

Книги з теми "Magnetotelluric inversion"

1

Vserossiĭskiĭ shkola-seminar po ėlektromagnitnyi zondirovani Zemli (1st 2005 Moscow, Russia). Ėlektromagnitnye issledovanii︠a︡ zemnykh nedr. Moskva: Nauchnyĭ mir, 2005.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Xiao, Xiao, and Liu Changsheng, eds. Bei dong yuan dian ci ce shen zi shi ying shi liang you xian yuan ji shuang mo fan yan. Changsha Shi: Zhong nan da xue chu ban she, 2010.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Siripunvaraporn, Weerachai. An efficient data-subspace two-dimensional magnetotelluric inversion and its application to high resolution profile across the San Andreas Faults at Parkfield, California. 1999.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Siripunvaraporn, Weerachai. An efficient data-subspace two-dimensional magnetotelluric inversion and its application to high resolution profile across the San Andreas Faults at Parkfield, California. 1999.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Geological Survey (U.S.), ed. Nonlinear least-squares inversion of infinite line source data (Program NLSINF). Denver, Colo: U.S. Dept. of the Interior, Geological Survey, 1989.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Geological Survey (U.S.), ed. Nonlinear least-squares inversion of infinite line source data (Program NLSINF). Denver, Colo: U.S. Dept. of the Interior, Geological Survey, 1989.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Geological Survey (U.S.), ed. Nonlinear least-squares inversion of infinite line source data (Program NLSINF). Denver, Colo: U.S. Dept. of the Interior, Geological Survey, 1989.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Geological Survey (U.S.), ed. Nonlinear least-squares inversion of infinite line source data (Program NLSINF). Denver, Colo: U.S. Dept. of the Interior, Geological Survey, 1989.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Geological Survey (U.S.), ed. SAKI: A Fortran program for generalized linear inversion of gravity and magnetic profiles. [Reston, Va.?]: U.S. Dept. of the Interior, Geological Survey, 1985.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

SAKI: A Fortran program for generalized linear inversion of gravity and magnetic profiles. [Reston, Va.?]: U.S. Dept. of the Interior, Geological Survey, 1985.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Більше джерел

Частини книг з теми "Magnetotelluric inversion"

1

Xiao, Yi, Pengdong Gao, and Yongquan Lu. "Improved Parallel Gaussian Elimination Algorithm in Magnetotelluric Occam’s Inversion." In Intelligent Computing Theories and Application, 591–600. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-42294-7_53.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Xiao, Yi, and Yu Liu. "GPU Acceleration for the Gaussian Elimination in Magnetotelluric Occam Inversion Algorithm." In Proceedings of the 4th International Conference on Computer Engineering and Networks, 123–31. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-11104-9_15.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Foudili, Djabir, Abderrezak Bouzid, and Mohamed Chérif Berguig. "2-D Resistivity Model of Magnetotelluric Inversion from M’rara Area, Algerian Sahara‏." In On Significant Applications of Geophysical Methods, 85–87. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-01656-2_19.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Berdichevsky, Mark, and Vladimir I. Dmitriev. "Inversion Strategy." In Models and Methods of Magnetotellurics, 453–544. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-77814-1_12.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

"11. Multidimensional Magnetotelluric Inversion." In Magnetotellurics in the Context of the Theory of Ill-Posed Problems, 146–66. Society of Exploration Geophysicists, 2002. http://dx.doi.org/10.1190/1.9781560802068.ch11.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Whittall, Kenneth P., and Douglas W. Oldenburg. "1. Introduction." In Inversion of Magnetotelluric Data for a One-Dimensional Conductivity, 1–6. Society of Exploration Geophysicists, 1992. http://dx.doi.org/10.1190/1.9781560802419.ch1.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Whittall, Kenneth P., and Douglas W. Oldenburg. "10. Conclusions." In Inversion of Magnetotelluric Data for a One-Dimensional Conductivity, 101–6. Society of Exploration Geophysicists, 1992. http://dx.doi.org/10.1190/1.9781560802419.ch10.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Whittall, Kenneth P., and Douglas W. Oldenburg. "2. Existence." In Inversion of Magnetotelluric Data for a One-Dimensional Conductivity, 7–12. Society of Exploration Geophysicists, 1992. http://dx.doi.org/10.1190/1.9781560802419.ch2.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Whittall, Kenneth P., and Douglas W. Oldenburg. "3. Uniqueness." In Inversion of Magnetotelluric Data for a One-Dimensional Conductivity, 13–14. Society of Exploration Geophysicists, 1992. http://dx.doi.org/10.1190/1.9781560802419.ch3.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Whittall, Kenneth P., and Douglas W. Oldenburg. "4. Asymptotic Methods." In Inversion of Magnetotelluric Data for a One-Dimensional Conductivity, 15–39. Society of Exploration Geophysicists, 1992. http://dx.doi.org/10.1190/1.9781560802419.ch4.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "Magnetotelluric inversion"

1

Alyousuf, Taqi, and Li Yaoguo. "Inversion Using Adaptive Physics-Based Neural Network: Application to Magnetotelluric Inversion." In International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-22504-ea.

Повний текст джерела
Анотація:
Abstract In order to develop a geophysical earth model that is consistent with the measured geophysical data, two types of inversions are commonly used: a physics-based regularized inversion and a statistical-based machine learning inversion. In nonlinear problems, deterministic regularized inversion usually necessitates a good starting model to prevent possible local minima. The neural networks inversion requires large training data sets, which makes its generalizability limited. To overcome the limitation of physics-based regularized inversion and a statistical-based machine learning inversion and combine the benefits of both one inversion scheme, we developed a new physics-based neural network (PBNN) inversion algorithm. In our PBNN inversion, we include machine learning constraints into the regularized inversion using a coupling model objective function. The coupling objective function aims to minimize the difference between the recovered model through regularized inversion and the network-predicted reference model. We update the reference model using either a fully-trained network or an adaptively-trained network. The fully trained PBNN has the ability to collect all of the connections between data and models through a pseudoinverse operator. However, for geophysical inversion applications, particularly in the exploratory setting, this approach is unlikely to become feasible. Neural networks may struggle to extract complicated correlations from data when given insufficient data observations. The technique is impractical for practical usage due to the quantity of training required. In our novel adaptively PBNN algorithm, there is no need to prepare a training data set. At each iteration, the adaptively-PBNN algorithm retrains using the recovered models from the regularized inversion and their related data. The regularized inversion's recovered resistivity models are sufficient to guide neural network predictions towards the true model. One unique advantage is that the approach’s ability to fully use all intermediate models from the regularized inversion that were commonly discarded and apply them to the network training. When applied to synthetic MT data, we show that our technique is capable of reconstructing high-resolution resistivity models.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Gouvęa Luiz, J., and L. Rijo. "Multidimensional Inversion of Magnetotelluric Data." In 4th International Congress of the Brazilian Geophysical Society. European Association of Geoscientists & Engineers, 1995. http://dx.doi.org/10.3997/2214-4609-pdb.313.193.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Srnka, L. J. "Riccati inversion of magnetotelluric data." In SEG Technical Program Expanded Abstracts 1986. Society of Exploration Geophysicists, 1986. http://dx.doi.org/10.1190/1.1893057.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Wittke, Jan, and Bülent Tezkan. "Meshless inversion of magnetotelluric data." In SEG Technical Program Expanded Abstracts 2018. Society of Exploration Geophysicists, 2018. http://dx.doi.org/10.1190/segam2018-2994813.1.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Mehanee, Salah, Nikolay Golubev, and Michael S. Zhdanov. "Weighted regularized inversion of magnetotelluric data." In SEG Technical Program Expanded Abstracts 1998. Society of Exploration Geophysicists, 1998. http://dx.doi.org/10.1190/1.1820468.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Golfré Andreasi, F., S. Re, F. Ceci, L. Masnaghetti, and A. Battaglini. "Geologically-Driven Inversion of Magnetotelluric Data." In 2nd Conference on Geophysics for Mineral Exploration and Mining. Netherlands: EAGE Publications BV, 2018. http://dx.doi.org/10.3997/2214-4609.201802707.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Manuel Ramos, Fernando, and Haroldo Fraga de Campos Velho. "A New Regularization Technique in Magnetotelluric Inversion." In 5th International Congress of the Brazilian Geophysical Society. European Association of Geoscientists & Engineers, 1997. http://dx.doi.org/10.3997/2214-4609-pdb.299.203.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Régis, Cícero, and Luiz Rijo. "1-D Inversion of Anisotropic Magnetotelluric Data." In 5th International Congress of the Brazilian Geophysical Society. European Association of Geoscientists & Engineers, 1997. http://dx.doi.org/10.3997/2214-4609-pdb.299.213.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Michael Hoversten, G., T. Smith, and E. Gasperikova. "Sharp Boundary Inversion of 2D Magnetotelluric Data." In 59th EAGE Conference & Exhibition. European Association of Geoscientists & Engineers, 1997. http://dx.doi.org/10.3997/2214-4609-pdb.131.gen1997_f023.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Zhdanov, Michael S., Nikolay Golubev, Le Wan, Olex Ingerov, and Leo Fox. "Cascade 3‐D inversion of magnetotelluric data." In SEG Technical Program Expanded Abstracts 2004. Society of Exploration Geophysicists, 2004. http://dx.doi.org/10.1190/1.1845281.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Звіти організацій з теми "Magnetotelluric inversion"

1

Booker, J. R. Two and three dimensional magnetotelluric inversion. Office of Scientific and Technical Information (OSTI), July 1994. http://dx.doi.org/10.2172/10163831.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Booker, J. Two and three dimensional magnetotelluric inversion. Office of Scientific and Technical Information (OSTI), January 1993. http://dx.doi.org/10.2172/6602656.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Smith, J. Rapid inversion of multi-dimensional magnetotelluric data. Office of Scientific and Technical Information (OSTI), August 1988. http://dx.doi.org/10.2172/5464900.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Booker, J. Two and three dimensional magnetotelluric inversion. Final report. Office of Scientific and Technical Information (OSTI), May 1993. http://dx.doi.org/10.2172/10147909.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Booker, J. R. Two and three-dimensional magnetotelluric inversion. Technical report, December 1, 1991--May 31, 1994. Office of Scientific and Technical Information (OSTI), June 1994. http://dx.doi.org/10.2172/10163836.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Craven, J. A., B. J. Roberts, N. Hayward, M. Stefanescu, and L. Corriveau. A magnetotelluric survey and preliminary geophysical inversion and visualization of the NICO IOCG deposit, Northwest Territories. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2013. http://dx.doi.org/10.4095/292869.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Ansari, S. M., E. M. Schetselaar, and J. A. Craven. Three-dimensional magnetotelluric modelling of the Lalor volcanogenic massive-sulfide deposit, Manitoba. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/328003.

Повний текст джерела
Анотація:
Unconstrained magnetotelluric inversion commonly produces insufficient inherent resolution to image ore-system fluid pathways that were structurally thinned during post-emplacement tectonic activity. To improve the resolution in these complex environments, we synthesized the 3-D magnetotelluric (MT) response for geologically realistic models using a finite-element-based forward-modelling tool with unstructured meshes and applied it to the Lalor volcanogenic massive-sulfide deposit in the Snow Lake mining camp, Manitoba. This new tool is based on mapping interpolated or simulated resistivity values from wireline logs onto unstructured tetrahedral meshes to reflect, with the help of 3-D models obtained from lithostratigraphic and lithofacies drillhole logs, the complexity of the host-rock geological structure. The resulting stochastic model provides a more realistic representation of the heterogeneous spatial distribution of the electric resistivity values around the massive, stringer, and disseminated sulfide ore zones. Both models were combined into one seamless tetrahedral mesh of the resistivity field. To capture the complex resistivity distribution in the geophysical forward model, a finite-element code was developed. Comparative analyses of the forward models with MT data acquired at the Earth's surface show a reasonable agreement that explains the regional variations associated with the host rock geological structure and detects the local anomalies associated with the MT response of the ore zones.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Ansari, S. M., J. A. Craven, and E. Schetselaar. Three-dimensional forward modelling and inversion of magnetotelluric data using unstructured meshes for understanding realistic geological systems: method development, algorithms and model construction for the Lalor deposit, Manitoba. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2019. http://dx.doi.org/10.4095/313656.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Goodwin, J. A., W. Jiang, A. J. Meixner, S. R. B. McAlpine, S. Buckerfield, M. G. Nicoll, and M. Crowe. Estimating cover thickness in the Southern Thomson Orogen: results from the pre-drilling application of refraction seismic, audio-magnetotelluric and targeted magnetic inversion modelling methods on proposed borehole sites. Geoscience Australia, 2017. http://dx.doi.org/10.11636/record.2017.021.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Також вас можуть зацікавити розширені добірки на тему "Magnetotelluric inversion" для конкретних типів джерел:
Статті в журналах Дисертації Книги
Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!

До бібліографії