Relevant bibliographies by topics / Body wave tomography

Academic literature on the topic 'Body wave tomography'

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Published: 14 March 2023

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Journal articles on the topic "Body wave tomography"

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Mercier, J. P., M. G. Bostock, J. F. Cassidy, K. Dueker, J. B. Gaherty, E. J. Garnero, J. Revenaugh, and G. Zandt. "Body-wave tomography of western Canada." Tectonophysics 475, no. 3-4 (October 2009): 480–92. http://dx.doi.org/10.1016/j.tecto.2009.05.030.

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Karimpour, Mohammadkarim, Evert Cornelis Slob, and Laura Valentina Socco. "Physically Constrained 2D Joint Inversion of Surface and Body Wave Tomography." Journal of Environmental and Engineering Geophysics 27, no. 2 (June 2022): 57–71. http://dx.doi.org/10.32389/jeeg21-031.

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Joint inversion of different geophysical methods is a powerful tool to overcome the limitations of individual inversions. Body wave tomography is used to obtain P-wave velocity models by inversion of P-wave travel times. Surface wave tomography is used to obtain S-wave velocity models through inversion of the dispersion curves data. Both methods have inherent limitations. We focus on the joint body and surface waves tomography inversion to reduce the limitations of each individual inversion. In our joint inversion scheme, the Poisson ratio was used as the link between P-wave and S-wave velocities, and the same geometry was imposed on the final velocity models. The joint inversion algorithm was applied to a 2D synthetic dataset and then to two 2D field datasets. We compare the obtained velocity models from individual inversions and the joint inversion. We show that the proposed joint inversion method not only produces superior velocity models but also generates physically more meaningful and accurate Poisson ratio models.
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Maupin, Valérie. "Combining asynchronous data sets in regional body-wave tomography." Geophysical Journal International 224, no. 1 (October 5, 2020): 401–15. http://dx.doi.org/10.1093/gji/ggaa473.

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SUMMARY Regional body-wave tomography is a very popular tomographic method consisting in inverting relative traveltime residuals of teleseismic body waves measured at regional networks. It is well known that the resulting inverse seismic model is relative to an unknown vertically varying reference model. If jointly inverting data obtained with networks in the vicinity of each other but operating at different times, the relative velocity anomalies in different areas of the model may have different reference levels, possibly introducing large-scale biases in the model that may compromise the interpretation. This is very unfortunate as we have numerous examples of asynchronous network deployments which would benefit from a joint analysis. We show here how a simple improvement in the formulation of the sensitivity kernels allows us to mitigate this problem. Using sensitivity kernels that take into account that data processing implies a zero mean residual for each event, the large-scale biases that otherwise arise in the inverse model using data from asynchronous station deployment are largely removed. We illustrate this first with a very simple 3-station example, and then compare the results obtained using the usual and the relative kernels in synthetic tests with more realistic station coverage, simulating data acquisition at two neighbouring asynchronous networks.
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Catchings, Rufus D., Michael J. Rymer, and Mark R. Goldman. "San Andreas Fault Exploration Using Refraction Tomography and S-Wave-Type and Fϕ-Mode Guided Waves." Bulletin of the Seismological Society of America 110, no. 6 (July 21, 2020): 3088–102. http://dx.doi.org/10.1785/0120200136.

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ABSTRACT Surface ruptures from the 18 April 1906 M∼7.9 San Francisco earthquake were distributed over an ∼35-meter-wide zone at San Andreas Lake on the San Francisco Peninsula in California (Schussler, 1906). Since ∼1906, the surface ruptures have been largely covered by water, but with water levels at near-historic low levels in 2008–2011, we observed that the 1906 surface ruptures were no longer visible. As a fault imaging test, we acquired refraction tomography and guided-wave data across the 1906 surface ruptures in 2011. We found that individual fault traces, as mapped by Schussler (1906), can be identified on the basis of discrete low-velocity zones (VS and VP, reduced ∼40% and ∼34%, respectively) and high-amplitude guided waves. Guided waves have traditionally been observed as large-amplitude waveforms over wide (hundreds of meters to kilometers) zones of faulting, but we demonstrate that by evaluating guided waves (including Rayleigh/Love- and P/SV-types) in terms of peak ground velocity (PGV), individual near-surface fault traces within a fault zone can be precisely located, even more than 100 yr after the surface ruptures. Such precise exploration can be used to focus paleoseismic trenching efforts and to identify or exclude faulting at specific sites. We evaluated PGV of both S-wave-type and Fϕ-mode-type guided waves and found that both wave types can be used to identify subsurface fault traces. At San Andreas Lake (main fault), S-wave-type guided waves travel up to 18% slower than S body waves, and Fϕ-mode guided waves travel ∼60% slower than P body waves but ∼15% faster than S body waves. We found that guided-wave amplitudes vary with frequency but are up to five times higher than those of body waves, including the S wave. Our data are consistent with the concept that guided waves can be a strong-shaking hazard during large-magnitude earthquakes.
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Tran, Khiem T., Michael McVay, Michael Faraone, and David Horhota. "Sinkhole detection using 2D full seismic waveform tomography." GEOPHYSICS 78, no. 5 (September 1, 2013): R175—R183. http://dx.doi.org/10.1190/geo2013-0063.1.

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We have developed an application of 2D time-domain waveform tomography for detection of embedded sinkholes and anomalies. The measured seismic surface wavefields were inverted using a full-waveform inversion (FWI) technique, based on a finite-difference solution of 2D elastic wave equations and the Gauss-Newton inversion method. The key advantage of this approach is the ability to generate all possible wave propagation modes of seismic wavefields (body waves and Rayleigh waves) that are then compared with measured data to infer complex subsurface properties.The pressure-wave (P-wave) and shear-wave (S-wave) velocities are inverted independently and simultaneously. The FWI was applied to one synthetic and two real experimental data sets. The inversion results of synthetic data showed the useful capability of the waveform analysis in identifying an embedded void. The inversion results of real data sets showed that the waveform analysis was able to delineate (1) an embedded concrete culvert and (2) a complex profile with an embedded void and highly variable bedrock laterally and vertically. An independent invasive test (standard penetration test) was also conducted to verify the seismic test results.
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Zhang, Xin, Corinna Roy, Andrew Curtis, Andy Nowacki, and Brian Baptie. "Imaging the subsurface using induced seismicity and ambient noise: 3-D tomographic Monte Carlo joint inversion of earthquake body wave traveltimes and surface wave dispersion." Geophysical Journal International 222, no. 3 (May 9, 2020): 1639–55. http://dx.doi.org/10.1093/gji/ggaa230.

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SUMMARY Seismic body wave traveltime tomography and surface wave dispersion tomography have been used widely to characterize earthquakes and to study the subsurface structure of the Earth. Since these types of problem are often significantly non-linear and have non-unique solutions, Markov chain Monte Carlo methods have been used to find probabilistic solutions. Body and surface wave data are usually inverted separately to produce independent velocity models. However, body wave tomography is generally sensitive to structure around the subvolume in which earthquakes occur and produces limited resolution in the shallower Earth, whereas surface wave tomography is often sensitive to shallower structure. To better estimate subsurface properties, we therefore jointly invert for the seismic velocity structure and earthquake locations using body and surface wave data simultaneously. We apply the new joint inversion method to a mining site in the United Kingdom at which induced seismicity occurred and was recorded on a small local network of stations, and where ambient noise recordings are available from the same stations. The ambient noise is processed to obtain inter-receiver surface wave dispersion measurements which are inverted jointly with body wave arrival times from local earthquakes. The results show that by using both types of data, the earthquake source parameters and the velocity structure can be better constrained than in independent inversions. To further understand and interpret the results, we conduct synthetic tests to compare the results from body wave inversion and joint inversion. The results show that trade-offs between source parameters and velocities appear to bias results if only body wave data are used, but this issue is largely resolved by using the joint inversion method. Thus the use of ambient seismic noise and our fully non-linear inversion provides a valuable, improved method to image the subsurface velocity and seismicity.
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Clarke, Timothy J. "The complete ordered ray expansion-II. Multiphase body wave tomography." Geophysical Journal International 115, no. 2 (November 1993): 435–44. http://dx.doi.org/10.1111/j.1365-246x.1993.tb01197.x.

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Shomali, Z. Hossein, and Roland G. Roberts. "Non-linear body wave teleseismic tomography along the TOR array." Geophysical Journal International 148, no. 3 (March 27, 2002): 562–74. http://dx.doi.org/10.1046/j.1365-246x.2002.01592.x.

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Catheline, Stefan. "Passive elastography: A shear wave tomography of the human body." Journal of the Acoustical Society of America 141, no. 5 (May 2017): 3527. http://dx.doi.org/10.1121/1.4987440.

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Stähler, S. C., K. Sigloch, and T. Nissen-Meyer. "Triplicated P-wave measurements for waveform tomography of the mantle transition zone." Solid Earth Discussions 4, no. 2 (July 2, 2012): 783–821. http://dx.doi.org/10.5194/sed-4-783-2012.

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Abstract. Triplicated body waves sample the mantle transition zone more extensively than any other wave type, and interact strongly with the discontinuities at 410 km and 660 km. Since the seismograms bear a strong imprint of these geodynamically interesting features, it is highly desirable to invert them for structure of the transition zone. This has rarely been attemped, due to the mismatch between the complex and bandlimited data and the (ray-theoretical) modeling methods. Here we present a data processing and modeling strategy to harness such broadband seismograms for finite-frequency tomography. We include triplicated P-waves (epicentral distance range between 14 and 30°) across their entire broadband frequency range, for both deep and shallow sources. We show that it is possible to predict the complex sequence of arrivals in these seismograms, but only after a careful effort to estimate source time functions and other source parameters from data, variables that strongly influence the waveforms. Modeled and observed waveforms then yield decent cross-correlation fits, from which we measure finite-frequency traveltime anomalies. We discuss two such data sets, for North America and Europe, and conclude that their signal quality and azimuthal coverage should be adequate for tomographic inversion. In order to compute sensitivity kernels at the pertinent high body-wave frequencies, we use fully numerical forward modelling of the seismic wavefield through a spherically symmetric earth.
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Dissertations / Theses on the topic "Body wave tomography"

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Baumann-Wilke, Maria. "Combining body wave tomography, surface wave inversion, seismic interferometry and laboratory measurements to characterize the black shales on Bornholm at different scales." Phd thesis, Universität Potsdam, 2013. http://opus.kobv.de/ubp/volltexte/2013/6900/.

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Black shales are sedimentary rocks with a high content of organic carbon, which leads to a dark grayish to black color. Due to their potential to contain oil or gas, black shales are of great interest for the support of the worldwide energy supply. An integrated seismic investigation of the Lower Palaeozoic black shales was carried out at the Danish island Bornholm to locate the shallow-lying Alum Shale layer and its surrounding formations and to characterize its potential as a source rock. Therefore, two seismic experiments at a total of three crossing profiles were carried out in October 2010 and in June 2012 in the southern part of the island. Two different active measurements were conducted with either a weight drop source or a minivibrator. Additionally, the ambient noise field was recorded at the study location over a time interval of about one day, and also a laboratory analysis of borehole samples was carried out. The seismic profiles were positioned as close as possible to two scientific boreholes which were used for comparative purposes. The seismic field data was analyzed with traveltime tomography, surface wave inversion and seismic interferometry to obtain the P-wave and S-wave velocity models of the subsurface. The P-wave velocity models which were determined for all three profiles clearly locate the Alum Shale layer between the Komstad Limestone layer on top and the Læså Sandstone Formation at the base of the models. The black shale layer has P-wave velocities around 3 km/s which are lower compared to the adjacent formations. Due to a very good agreement of the sonic log and the vertical velocity profiles of the two seismic lines, which are directly crossing the borehole where the sonic log was conducted, the reliability of the traveltime tomography is proven. A correlation of the seismic velocities with the content of organic carbon is an important task for the characterization of the reservoir properties of a black shale formation. It is not possible without calibration but in combination with a full 2D tomographic image of the subsurface it gives the subsurface distribution of the organic material. The S-wave model obtained with surface wave inversion of the vibroseis data of one of the profiles images the Alum Shale layer also very well with S-wave velocities around 2 km/s. Although individual 1D velocity models for each of the source positions were determined, the subsurface S-wave velocity distribution is very uniform with a good match between the single models. A really new approach described here is the application of seismic interferometry to a really small study area and a quite short time interval. Also new is the selective procedure of only using time windows with the best crosscorrelation signals to achieve the final interferograms. Due to the small scale of the interferometry even P-wave signals can be observed in the final crosscorrelations. In the laboratory measurements the seismic body waves were recorded for different pressure and temperature stages. Therefore, samples of different depths of the Alum Shale were available from one of the scientific boreholes at the study location. The measured velocities have a high variance with changing pressure or temperature. Recordings with wave propagation both parallel and perpendicular to the bedding of the samples reveal a great amount of anisotropy for the P-wave velocity, whereas the S-wave velocity is almost independent of the wave direction. The calculated velocity ratio is also highly anisotropic with very low values for the perpendicular samples and very high values for the parallel ones. Interestingly, the laboratory velocities of the perpendicular samples are comparable to the velocities of the field experiments indicating that the field measurements are sensitive to wave propagation in vertical direction. The velocity ratio is also calculated with the P-wave and S-wave velocity models of the field experiments. Again, the Alum Shale can be clearly separated from the adjacent formations because it shows overall very low vP/vS ratios around 1.4. The very low velocity ratio indicates the content of gas in the black shale formation. With the combination of all the different methods described here, a comprehensive interpretation of the seismic response of the black shale layer can be made and the hydrocarbon source rock potential can be estimated.
Schwarzschiefer sind Sedimentgesteine, die einen hohen Gehalt an organischem Kohlenstoff aufweisen, was zu einer dunkelgrauen bis schwarzen Färbung führt. Da Schwarzschiefer das Potenzial besitzen, Öl oder Gas zu enthalten und somit zur weltweiten Energieversorgung beitragen könnten, sind sie von großem Interesse. Mit Hilfe der Kombination verschiedener seismischer Messverfahren wurden die Schwarzschiefer des Unteren Paläozoikums auf der dänischen Insel Bornholm untersucht um den oberflächennahen Alaunschiefer und dessen Umgebungsgestein dort zu lokalisieren und sein Potenzial als Muttergestein abzuschätzen. Dafür wurden im Oktober 2010 und im Juni 2012 im südlichen Teil der Insel zwei seismische Experimente auf insgesamt drei sich kreuzenden Profilen durchgeführt. Für zwei aktive seismische Messungen wurden ein Fallgewicht und ein Minivibrator als Quellen genutzt. Zusätzlich wurde im Messgebiet noch das Wellenfeld des umgebenden Rauschens über einen Zeitraum von etwa einem Tag aufgezeichnet. Außerdem wurden Labormessungen an Bohrkernen aus dem Alaunschiefer durchgeführt. Die seismischen Messprofile befanden sich so nah wie möglich an zwei wissenschaftlichen Bohrungen, die für Vergleichszwecke genutzt wurden. Um die P- und S-Wellengeschwindigkeitsmodelle des Untergrundes zu erhalten wurden die seismischen Felddaten mittels Laufzeittomographie, Oberflächenwelleninversion und seismischer Interferometrie ausgewertet. Die P-Wellenmodelle, die für alle drei seismischen Profile erstellt wurden, zeigen den Alaunschiefer zwischen dem Komstad Kalkstein, der den Alaunschiefer überdeckt, und der Læså Sandsteinformation, die die Basis der Modelle bildet. Für die Schwarzschieferschicht ergeben sich mit rund 3 km/s deutlich geringere P-Wellengeschwindigkeiten als für die umgebenden Gesteine. Zwei seismische Profile liegen direkt an einer der Bohrungen, für die verschiedene Bohrloch-Logs durchgeführt wurden. Der Vergleich des Sonic-Logs mit den vertikalen Geschwindigkeitsprofilen beider Modelle am Bohrpunkt zeigt eine sehr gute übereinstimmung aller Geschwindigkeiten. Dies ist ein Indiz für die Plausibilität der durchgeführten Laufzeittomographie. Um die Reservoireigenschaften der Schwarzschieferschicht einordnen zu können, wurde versucht, die seismischen Geschwindigkeiten mit dem Gehalt an organischem Material zu korrelieren. Ohne geeignete Kalibrierung ist diese Korrelation schwierig, kann aber mit Hilfe der Tomographieergebnisse ein zweidimensionales Abbild der Verteilung des organischen Materials im Untergrund liefern. Auch das S-Wellengeschwindigkeitsmodell, welches mit der Oberflächenwelleninversion der Vibroseisdaten erstellt wurde, bildet den Alaunschiefer gut ab. Hierbei zeigen sich S-Wellengeschwindigkeiten um 2 km/s. Obwohl jeweils nur 1D-Modelle für jede Quellposition bestimmt wurden, ergibt sich für die gesamte Untergrundstruktur des untersuchten Profils ein einheitliches Bild der Geschwindigkeiten. Einen sehr neuen Ansatz bildet die Anwendung der seismischen Interferometrie auf ein sehr kleines Untersuchungsgebiet und über einen sehr kurzen Zeitraum. Neu ist außerdem, dass für die Bestimmung der endgültigen Interferogramme nur Zeitfenster der Kreuzkorrelationen ausgewählt werden, in denen die Signalqualität hinreichend gut ist. In den berechneten Kreuzkorrelationen sind sogar P-Wellen enthalten, was auf die geringen Abstände der seismischen Rekorder zurück zu führen ist. Bei den Labormessungen wurden die Raumwellen für verschiedene Drücke und Temperaturen aufgezeichnet. Die Messungen der Geschwindigkeiten sowohl parallel als auch senkrecht zur Schichtung der Proben zeigen eine starke Anisotropie für die P-Welle. Dagegen scheint die S-Wellengeschwindigkeit fast unabhängig von der Ausbreitungsrichtung der Wellen zu sein. Auch das Verhältnis der Geschwindigkeiten weist starke Anisotropie auf. Für die Wellenausbreitung senkrecht zur Schichtung zeigen sich sehr niedrige Werte, die Werte für die Messungen parallel zur Schichtung sind dagegen deutlich erhöht. Ein interessanter Aspekt der aus den Labormessungen resultiert ist, dass die Geschwindigkeit der Messungen senkrecht zur Schichtung mit den Geschwindigkeitswerten der Feldmessungen übereinstimmen. Damit scheinen die Feldmessungen besonders die Ausbreitung der Wellen in vertikaler Richtung zu registrieren. Das Geschwindigkeitsverhältnis wurde auch mit den P- und S-Wellenmodellen der Feldexperimente berechnet. Auch hier hebt sich der Alaunschiefer mit deutlich verringerten Werten um 1.4 vom Umgebungsgestein ab. Solch geringe Werte für das Verhältnis der Geschwindigkeiten deutet auf den Gehalt von Gas im Schwarzschiefer. Mit der Kombination der verschiedenen Methoden ist es möglich, die seismische Antwort der Schwarzschieferschicht umfassend zu beschreiben und Schlussfolgerungen darüber zu ziehen, ob die hier untersuchte Schwarzschieferschicht das Potenzial hat als Kohlenwasserstofflagerstätte zu fungieren.
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Arlitt, Robert. "Teleseismic body wave tomography across the Trans-European suture zone between Sweden and Denmark /." [S.l.] : [s.n.], 1999. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13501.

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Baumann-Wilke, Maria [Verfasser], and Michael [Akademischer Betreuer] Weber. "Combining body wave tomography, surface wave inversion, seismic interferometry and laboratory measurements to characterize the black shales on Bornholm at different scales / Maria Baumann-Wilke. Betreuer: Michael Weber." Potsdam : Universitätsbibliothek der Universität Potsdam, 2013. http://d-nb.info/1045780693/34.

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Eken, Tuna. "Isotropic and Anisotropic P and S Velocities of the Baltic Shield Mantle : Results from Analyses of Teleseismic Body Waves." Doctoral thesis, Uppsala universitet, Geofysik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-102501.

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The upper mantle structure of Swedish part of Baltic Shield with its isotropic and anisotropic seismic velocity characteristics is investigated using telesesismic body waves (i.e. P waves and shear waves) recorded by the Swedish National Seismological Network (SNSN). Nonlinear high-resolution P and SV and SH wave isotropic tomographic inversions reveal velocity perturbations of ± 3 % down to at least 470 km below the network. Separate SV and SV models indicate several consistent major features, many of which are also consistent with P-wave results. A direct cell by cell comparison of SH and SV models reveals velocity differences of up to 4%. Numerical tests show that differences in the two S-wave models can only be partially caused by noise and limited resolution, and some features are attributed to the effect of large scale anisotropy. Shear-wave splitting and P-travel time residual analyses also detect anisotropic mantle structure. Distinct back-azimuth dependence of SKS splitting excludes single-layer anisotropy models with horizontal symmetry axes for the whole region. Joint inversion using both the P and S data reveals 3D self-consistent anisotropic models with well-defined mantle lithospheric domains. These domains of differently oriented anisotropy most probably retain fossil fabric since the domains' origin, supporting the idea of the existence of an early form of plate tectonics during formation of continental cratons already in the Archean. The possible disturbing effects of anisotropy on seismic tomography studies are investigated, and found to be potentially significant. P-wave arrival times were adjusted based on the estimates of mantle anisotropy, and re-inverted. The general pattern of the velocity-perturbation images was similar but changed significantly in some places, including the disappearance of a slab-like structure identified in the inversion with the original data. Thus the analysis demonstrates that anisotropy of quite plausible magnitude can have a significant effect on the tomographic images, and should not be ignored. If, as we believe, our estimates of anisotropy are reasonably correct, then the model based on the adjusted data should give a more robust and correct image of the mantle structure.
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Stähler, Simon. "Finite-frequency tomography with complex body waves." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-172851.

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Seismische Tomographie ist die eindrücklichste und intuitivste Methode, Informationen über das tiefe Erdinnere, von der Kruste bis an die Kern-Mantel-Grenze zu erlangen. Die von entfernten Erdbeben aufgezeichneten Bodenbewegungen werden mit den für ein einfaches Erdmodell vorhergesagten verglichen, um ein verbessertes Modell zu erhalten. Dieses dreidimensionale Modell kann dann geodynamisch oder tektonisch interpretiert werden. Durch die Entwicklung leistungsfähiger Computersysteme kann die Ausbreitung seismischer Wellen mittlerweile im gesamten messbaren Frequenzbereich simuliert werden, sodass dieses gesamte Spektrum der Tomographie zur Verfügung steht. Die vorliegende Arbeit beschäftigt sich mit der Verbesserung der Wellenformtomographie. Zum einen wird die Nutzbarkeit eines komplexen Typs seismischer Wellen, der in der Mantelübergangszone zwischen 410 und 660 km Tiefe gestreuten triplizierten Wellen ge-zeigt. Diese Wellen versprechen eine erheblich bessere Auflösung der geodynamisch wichtigen Diskontinuitäten zwischen oberem und unterem Mantel als bisher verwendete teleseismische Wellen. Zum anderen wird der nichtlineare Einfluss des Erdbebenmodells auf die Wellenformtomographie untersucht. Mittels Bayesianischer Inferenz werden Wahrscheinlichkeitsdichten für die Herdparameter des Erdbebens, wie Tiefe, Momententensor und Quellfunktion bestimmt. Dazu wird zuvor ein Modell der Messunsicherheit und des Modellierungsfehlers in der Herdinversion bestimmt, das bis dato nicht vorlag. Dabei zeigt sich im Weiteren, dass der Effekt der Unsicherheit im Herdmodell eine nichtlineare und bisher weitgehend ignorierte Feh-lerquelle in der seismischen Tomographie ist. Dieses Ergebnis ermöglicht es, die Varianz seismischer Laufzeit- und Wellenformmessungen sowie die Kovarianz zwischen einzelnen Messstationen zu bestimmen. Die Ergebnisse dieser Arbeit können in Zukunft erheblich dazu beitragen, die Unsicherheiten der seismischen Tomographie quantitativ zu bestimmen, um eventuell vorhandene Artefakte zu zeigen und damit geologischen Fehlinterpretationen tomographischer Ergebnisse vorzubeugen.
Seismic tomography is the most impressive method of inferring a picture of the deep interiour of the Earth, from the lower crust to the core mantle boundary. Recordings of ground motions caused by distant earthquakes are used to refine an existing earth model, employing difference between measured and predicted data. The resulting three-dimensional models and images can be interpreted in terms of tectonics and large-scale geodynamics. The increase in computing power in the last decade has lead to an enormous progress in tomographic methods, which can now simulate and therefore exploit the whole frequency range of seismographic measurements. This thesis refines waveform tomography in its flavour of finite-frequency tomography. It first shows that complex wave types, like the those perturbed by the discontinuities in the mantle transition zone can be used for waveform tomography. Using these waves promise an improved resolution of the geodynamically important transition zone compared to the hitherto used teleseismic waves. A second part checks the nonlinear influence of the source model on waveform tomography. By the method of Bayesian inference, probability density functions of the source parameters depth, moment tensor, and the source time function are determined. For that, a model of the measurement uncertainties is necessary, which was hitherto not available and is derived from a large catalogue of source solutions. The results of the probabilistic source inversion allow to quantify the effect of source uncertainty on seismic tomography. This allows to estimate the variance of seismic travel-times and waveforms and also the covariance between different seismographic stations. The results of this work could improve uncertainty estimation in seismic tomography, show potential artifacts in the result and therefore avoid misinterpretation of tomographic images by geologists and others.
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Hosseini, Kasra [Verfasser], and Heiner [Akademischer Betreuer] Igel. "Global multiple-frequency seismic tomography using teleseismic and core-diffracted body waves / Kasra Hosseini. Betreuer: Heiner Igel." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2016. http://d-nb.info/1106854594/34.

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Stähler, Simon [Verfasser], and Heiner [Akademischer Betreuer] Igel. "Finite-frequency tomography with complex body waves : taking into account data uncertainty and correlation / Simon Stähler. Betreuer: Heiner Igel." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1059351021/34.

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Nunn, Ceri. "Tomographic images of the crust and upper mantle beneath the Tibetan Plateau : using body waves, surface waves and a joint inversion." Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708398.

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Abdulah, Agus. "Seismic body wave attenuation tomography beneath the Australasian region." Phd thesis, 2007. http://hdl.handle.net/1885/145930.

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Amirbekyan, Abel [Verfasser]. "The application of reproducing kernel based spline approximation to seismic surface and body wave tomography : theoretical aspects and numerical results / Abel Amirbekyan." 2007. http://d-nb.info/984778055/34.

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Book chapters on the topic "Body wave tomography"

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Thurber, Clifford H. "Seismic Tomography of the Lithosphere with Body Waves." In Seismic Motion, Lithospheric Structures, Earthquake and Volcanic Sources: The Keiiti Aki Volume, 717–37. Basel: Birkhäuser Basel, 2003. http://dx.doi.org/10.1007/978-3-0348-8010-7_12.

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Devine, Michelle F., Divyanshu Dubey, and Sean J. Pittock. "Hearing Loss, Imbalance, and Diplopia in a 44-Year-Old Man." In Mayo Clinic Cases in Neuroimmunology, edited by Andrew McKeon, B. Mark Keegan, and W. Oliver Tobin, 105–7. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780197583425.003.0032.

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A 44-year-old man sought care for new right-sided tinnitus and sensorineural hearing loss. He was treated with high-dose oral prednisone and acyclovir. Later, mild, intermittent dizziness developed, which progressed to constant, moderate dizziness and was exacerbated by sudden head movements. He participated in vestibular rehabilitation with only mild improvement. Within 5 months of tinnitus onset, horizontal binocular diplopia also developed. Examination showed spontaneous left-beating torsional nystagmus in primary gaze, down-beating nystagmus with leftward gaze, and right-beating torsional nystagmus in rightward gaze. Head impulse testing to the right produced a catch-up saccade. Dix-Hallpike maneuver in both positions led to leftward torsional nystagmus followed by down-beating nystagmus. He had full range of eye motion. There was evidence of asymmetric hearing loss on the right and moderate gait unsteadiness; he was able to complete only a few steps in tandem. Neurologic examination findings were otherwise normal. Oculomotor testing demonstrated abnormalities supportive of a central nervous system disorder. These included excessive square-wave jerks, impaired smooth pursuit, and direction-changing nystagmus. Results of cerebrospinal fluid studies included a normal opening pressure, pleocytosis, and increased protein concentration. Serum and cerebrospinal fluid paraneoplastic evaluations showed a unique immunofluorescence staining pattern on rodent brain tissue by patient immunoglobulin G, which was later confirmed to be immunoglobulin G antibodies to kelch like family member 11. Whole-body positron emission tomography showed a single anterior mediastinal mass, which was then resected. The patient was diagnosed with a paraneoplastic anti-kelch like family member 11 rhombencephalitis with an extratesticular seminoma. After removal of the mediastinal mass, intravenous methylprednisolone was started. The patient had symptom stabilization but no clinical improvement. Cyclophosphamide was added to the weekly pulse-dose intravenous corticosteroids. He had mild improvement in vertigo and gait imbalance. For symptomatic management of the vertigo, he received baclofen, citalopram, and vestibular rehabilitation. He continued to have slow improvement. After approximately 1 year of cyclophosphamide treatment, his gait normalized and nystagmus diminished, although he had persistent neurologic deficits including spontaneous down-beating nystagmus and a few intermittent square-wave jerks. The intravenous methylprednisolone infusions were tapered, with continued examination stability. After stable symptoms and examination findings, cyclophosphamide was discontinued. After discontinuation of cyclophosphamide, new central sensorineural hearing loss developed suddenly in his left ear. This improved with additional intravenous methylprednisolone treatment. Mycophenolate mofetil was also started, and corticosteroids were tapered. Repeated positron emission tomography of the body showed no recurrence of seminoma. Symptoms and audiography findings were stable after 10 months, so the patient elected to discontinue immunosuppression again and has remained stable. Kelch like family member 11 autoimmunity is a distinct paraneoplastic syndrome associated with encephalitis and testicular germ cell tumors (including seminoma).
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Conference papers on the topic "Body wave tomography"

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Karimpour, M., E. Slob, and L. V. Socco. "Joint Inversion of Surface Wave Tomography and Body Wave Tomography Applied to 2D Media." In 82nd EAGE Annual Conference & Exhibition. European Association of Geoscientists & Engineers, 2020. http://dx.doi.org/10.3997/2214-4609.202011637.

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Nakata*, Nori, Jason P. Chang, and Jesse F. Lawrence. "Body-wave extraction and tomography at Long Beach, CA, with ambient-noise interferometry." In SEG Technical Program Expanded Abstracts 2014. Society of Exploration Geophysicists, 2014. http://dx.doi.org/10.1190/segam2014-0800.1.

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Wiskin, James, Bilal Malik, Rajni Natesan, David Borup, Nasser Pirshafiey, Mark Lenox, and John Klock. "Full Wave 3D Inverse Scattering Transmission Ultrasound Tomography: Breast and Whole Body Imaging." In 2019 IEEE International Ultrasonics Symposium (IUS). IEEE, 2019. http://dx.doi.org/10.1109/ultsym.2019.8925778.

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El-Sherbiny, S. M., and Mohamed A. A. Eldosoky. "Continuous-wave Ultrasonic Tomography In the Presence of Relative Motion of Some Particles within the Rotating Body." In 2007 National Radio Science Conference. IEEE, 2007. http://dx.doi.org/10.1109/nrsc.2007.371412.

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Abdelqader, Mahmoud, Sameh Hamama, Usama Abdelqader, Arindam Kanrar, Refaat Zaki, and Mahmoud Eloribi. "Improving the Imaging of Pre-Messinian Reservoirs in the East Mediterranean Sea, Offshore Egypt, Using Converted Wave Attenuation, Full-Waveform Inversion and Reflection Tomography." In International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-21874-ea.

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Abstract The offshore eastern Mediterranean region has received increased international interest in the last decade for its hydrocarbon potential in the pre-salt traps. The presence of a heterogeneous Messinian-age salt layer and complex pre-Messinian structures pose very difficult challenges in seismic imaging. In this paper, we provide a detailed workflow for seismic data preconditioning and imaging which resolves the subsurface challenges of the Mediterranean. Broadband acquisition was used to collect seismic data, which combines the responses of dual-sensor receivers to remove the effect of the receiver ghost. Adaptive source de-ghosting was then applied to address the source-side ghost. Data was processed using robust multiple attenuation and converted wave attenuation (CWA). A high-resolution velocity model building and imaging workflow was designed as follows: Diving waves full-waveform inversion (FWI) to capture detailed velocity for the complex overburden, followed by post-salt reflection tomography. Born modeling-based reflection FWI to update the velocity heterogeneities inside the salt body followed by reflection tomography for the deep section. Reverse time migration (RTM) to handle the waveform multi-pathing. De-ghosting corrected the wavelet phase and expanded the usable frequency bandwidth, resulting in a broadband dataset for imaging. Robust multiple attenuation and converted wave attenuation (CWA) techniques aided in revealing the true geological dips beneath the salt and facilitated picking accurate residual move-outs during the velocity model building. RTM in conjunction with the high-resolution velocity model significantly improved imaging of complex salt structures and pre-salt reservoirs. At well locations, our workflow resulted in a very good match between the available well data and surface seismic in terms of markers depths and velocity trends. This paper presents a novel approach for modelling the velocity heterogeneities inside the complex Messinian-age salt formation using the Born modeling-based reflection FWI. In addition, salt-related strong converted waves were successfully attenuated, whereas previously the presence of this energy misled interpreters and caused anomalous velocity updates in similar geological settings in the Mediterranean.
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Mahvelati, Siavash, Alireza Kordjazi, and Joseph T. Coe. "Full-waveform tomography combining body and surface waves to characterize liquefaction hazards." In Symposium on the Application of Geophysics to Engineering and Environmental Problems 2021. Society of Exploration Geophysicists and Environment and Engineering Geophysical Society, 2021. http://dx.doi.org/10.4133/sageep.33-080.

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Townsend, Daniel J., Jonathan J. Stott, Ronald A. Roy, and Charles A. DiMarzio. "Ultrasound Modulation of Diffusive Optical Waves for Medical Imaging." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1605.

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Abstract Diffusive optical tomography [DOT] is a technique for imaging within the body. While DOT provides excellent results under good conditions, there are many situations (due to anatomy or other physical limitation) in which it suffers from a “limited view” problem. In this paper we discuss our work on a new technique for combining DOT with focused ultrasound to generate virtual sources of illumination. These virtual sources help overcome the limited view problem. We present our experimental results using laboratory tissue phantoms.
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Delassaux, Francois, Iraj Mortazavi, Vincent Herbert, and Charles Ribes. "Flow Simulation and Investigation Around a Estate Vehicle Using Hybrid Methods." In ASME 2022 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/fedsm2022-86921.

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Abstract In this work hybrid RANS/LES methods are adapted in order to simulate the flow around a realistic car geometry (estate vehicle). Numerical results are compared to in-house experiments. In order to achieve an accurate understanding of the flow behavior around the car geometry, a wide range of experiments are performed measuring forces, pressure coefficients and tomography for 3D description of the flow in the wake of the body.
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Wolf, Christian, and Ralf Hörnschemeyer. "Tomographic PIV Measurements in the Shear Layer of a Bluff-Body Wake Flow." In 41st AIAA Fluid Dynamics Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2011. http://dx.doi.org/10.2514/6.2011-3084.

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Fielding, Rebecca A., Reuben H. Kraft, X. G. Tan, Andrzej J. Przekwas, and Christopher D. Kozuch. "High Rate Impact to the Human Calcaneus: A Micromechanical Analysis." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-38930.

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An “underbody blast” (UBB) is the detonation of a mine or improvised explosive device (IED) underneath a vehicle. In recent military conflicts, the incidence of UBBs has led to severe injuries, specifically in the lower extremities The foot and ankle complex, particularly the calcaneus bone, may sustain significant damage. Despite the prevalence of calcaneal injuries, this bone’s unique properties and the progression of fracture and failure have not been adequately studied under high strain rate loading. This research discusses early efforts at creating a high-resolution computational model of the human calcaneus, with primary focus on modeling the fracture network through the complex microstructure of the bone and creating micromechanically-based constitutive models that can be used within full human body models. The ultimate goal of this ongoing research effort is to develop a micromechanics-based simulation of calcaneus fracture and fragmentation due to impact loading. With the goal of determining the basic mechanisms of stress propagation through the internal structure of the calcaneus, a two-dimensional model was employed for preliminary simulations with a plane-strain approximation. In this effort, a cadaveric calcaneus was scanned to a resolution of 55 μm using an industrial micro-computed tomography (microCT) scanner. A mid-sagittal plane slice of the scan was selected and post-processed to generate a 2D finite element mesh of the calcaneus that included marrow, trabecular bone, and cortical bone elements. The calcaneus was modeled using two-dimensional quadratic plane strain elements. A fixed boundary condition was applied to the portion of the calcaneus that, in situ, would be restrained by the talus. A displacement of 1.25 mm was applied to the heel of the calcaneus over 5 ms. In a typical result, following impact, the strain and stress are propagated throughout the cortical shell and then began to radiate into the bone into the bone along the trabeculae. Local stress concentrations can be observed in the trabecular structure in the posterior region of the bone following impact. Upon impact, cortical and trabecular bone show different stresses of 13MPa and 1 MPa, respectively, and exhibit complex high frequency responses. Observed results may offer insight into the wave interactions between the different materials comprising the calcaneus, such as impedance mismatch and refraction. Pore pressure in the marrow may be another important factor to consider in understanding stress propagation in the calcaneus.
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Reports on the topic "Body wave tomography"

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Haines, M. W., A. Gorbatov, B. Hejrani, R. Hassan, J. Zhao, F. Zhang, and A. M. Reading. AusArray: imaging the lithospheric mantle using body-wave tomography. Geoscience Australia, 2020. http://dx.doi.org/10.11636/134501.

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Preston, Leiph. P- and S-body wave tomography of the state of Nevada. Office of Scientific and Technical Information (OSTI), April 2010. http://dx.doi.org/10.2172/984164.

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Reiter, Delaine T., and William L. Rodi. Validated 3D Velocity Models in Asia from Joint Regional Body- and Surface-Wave Tomography. Fort Belvoir, VA: Defense Technical Information Center, February 2009. http://dx.doi.org/10.21236/ada501242.

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Toksoez, M. N., and Youshun Sun. P and S Wave Velocity Structure of the Crust and Upper Mantle Under China and Surrounding Areas From Body and Surface Wave Tomography. Fort Belvoir, VA: Defense Technical Information Center, March 2008. http://dx.doi.org/10.21236/ada486734.

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