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427 results on '"Virieux, J."'

1. Chapter 13 Modelling Seismic Wave Propagation for Geophysical Imaging

Author

Tago, J., Cruz-Atienza, V., Chaljub, E., Brossier, R., Coutant, O., Garambois, S., Prieux, V., Operto, S., Mercerat, D., Virieux, J., and Ribodetti, A.

Subjects
seismic wave, geophysical imaging, Boundary value problem, Finite element method, Free surface, Frequency domain, Seismology, Time domain, Velocity, bic Book Industry Communication::P Mathematics & science::PD Science: general issues
Abstract

The Earth is an heterogeneous complex media from the mineral composition scale (10−6m) to the global scale ( 106m). The reconstruction of its structure is a quite challenging problem because sampling methodologies are mainly indirect as potential methods (Günther et al., 2006; Rücker et al., 2006), diffusive methods (Cognon, 1971; Druskin & Knizhnerman, 1988; Goldman & Stover, 1983; Hohmann, 1988; Kuo & Cho, 1980; Oristaglio & Hohmann, 1984) or propagation methods (Alterman & Karal, 1968; Bolt & Smith, 1976; Dablain, 1986; Kelly et al., 1976; Levander, 1988; Marfurt, 1984; Virieux, 1986). Seismic waves belong to the last category. We shall concentrate in this chapter on the forward problem which will be at the heart of any inverse problem for imaging the Earth. The forward problem is dedicated to the estimation of seismic wavefields when one knows the medium properties while the inverse problem is devoted to the estimation of medium properties from recorded seismic wavefields.

Published
2012
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5. Assessing the reliability of local earthquake tomography for crustal imaging: 30 years of records in the Western Alps as a case study

Author

Virieux, J, Paul, A, Langlais, M, Janex, G, Guéguen, P, Helmstetter, A, Stehly, L, Virieux, J, Paul, A, Langlais, M, Janex, G, Guéguen, P, Helmstetter, A, and Stehly, L

Abstract

Local earthquake tomography (LET) is a popular method for inverting arrival time picks of local-regional earthquakes for P- and S-wave velocity and hypocenter parameters in seismically active regions. This popularity is due to some robust and well-documented open-source codes that are sometimes used as black boxes. The availability of a very complete time-pick database on the Western Alps gives us a chance to thoroughly investigate the influence of the numerous processes and parameters involved when applying LET to the Western Alps or similar targets. From a subset of high-quality manual picks (1989-2014), we compute preliminary P and S velocity models that are used to predict arrival times for later events and allow the selected fusion of picks downloaded from different seismological agencies for a consistent 33-year database (1989-2021). Different model reconstructions are proposed by selecting different subsets of the arrival time dataset. Aside data input into the LET, influence of initial stratified or three-dimensional velocity models and related initial earthquake locations is investigated together with grid discretization, Laplacian smoothing and damping parameters in the standard penalty approach commonly used by LET codes. These numerical parameters account for the expected limited resolution of seismic waves due to their finite-frequency content. Parameter selection is handled by the user, whereas frequency impact is only implicit in the onset picks. The earthquake distribution allows a reconstruction down to 40-km depth over an area of ∼ 500x500 km2. Robust features such as the high-velocity Ivrea body anomaly, and a deep low-velocity anomaly associated with crustal thickening underneath the mountain belt survive whatever the tomography strategy and parameters. Finally, a comparison with previous LET reconstructions suggests that finite-frequency content be explicitly incorporated through wave equation tomography to improve spatial resolution. This would

Published
2023
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6. Assessing the reliability of local earthquake tomography for crustal imaging: 30 yr of records in the Western Alps as a case study.

Author

Virieux, J, Paul, A, Langlais, M, Janex, G, Guéguen, P, Helmstetter, A, and Stehly, L

Subjects
*EARTHQUAKES, *EARTHQUAKE zones, *SEISMIC waves, *TOMOGRAPHY, *SEISMIC event location, *SEISMIC tomography, *FEATURE selection, *PALEOSEISMOLOGY
Abstract

Local earthquake tomography (LET) is a popular method for inverting arrival time picks of local-regional earthquakes for P - and S -wave velocities and hypocentre parameters in seismically active regions. This popularity is due to some robust and well-documented open-source codes that are sometimes used as black boxes. The availability of a very complete time-pick database on the Western Alps gives us a chance to thoroughly investigate the influence of the numerous processes and parameters involved when applying LET to the Western Alps or similar targets. From a subset of high-quality manual picks (1989–2014), we compute preliminary P and S velocity models that are used to predict arrival times for later events and allow the selected fusion of picks downloaded from different seismological agencies for a consistent 33-yr database (1989–2021). Different model reconstructions are proposed by selecting different subsets of the arrival time data set. Aside data input into the LET, influence of initial stratified or 3-D velocity models and related initial earthquake locations is investigated together with grid discretization, Laplacian smoothing and damping parameters in the standard penalty approach commonly used by LET codes. These numerical parameters account for the expected limited resolution of seismic waves due to their finite-frequency content. Parameter selection is handled by the user, whereas frequency impact is only implicit in the onset picks. The earthquake distribution allows a reconstruction down to 40-km depth over an area of ∼500 × 500 km2. Robust features such as the high-velocity Ivrea body anomaly, and a deep low-velocity anomaly associated with crustal thickening underneath the mountain belt survive whatever the tomography strategy and parameters. Finally, a comparison with previous LET reconstructions suggests that finite-frequency content be explicitly incorporated through wave equation tomography to improve spatial resolution. This would fully exploit observables collected from seismograms, albeit with a significant increase in computer costs. [ABSTRACT FROM AUTHOR]

Published
2024
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27. Transmission of light in deep sea water at the site of the A ntares neutrino telescope

Author

Aguilar, J.A., Albert, A., Amram, P., Anghinolfi, M., Anton, G., Anvar, S., Ardellier-Desages, F.E., Aslanides, E., Aubert, J-J., Azoulay, R., Bailey, D., Basa, S., Battaglieri, M., Becherini, Y., Bellotti, R., Beltramelli, J., Bertin, V., Billault, M., Blaes, R., Blanc, F., Bland, R.W., de Botton, N., Boulesteix, J., Bouwhuis, M.C., Brooks, C.B., Bradbury, S.M., Bruijn, R., Brunner, J., Bugeon, F., Burgio, G.F., Cafagna, F., Calzas, A., Caponetto, L., Carmona, E., Carr, J., Cartwright, S.L., Cecchini, S., Charvis, P., Circella, M., Colnard, C., Compère, C., Croquette, J., Cooper, S., Coyle, P., Cuneo, S., Damy, G., van Dantzig, R., Deschamps, A., Marzo, C. De, Destelle, J.-J., Vita, R. De, Dinkelspiler, B., Dispau, G., Drougou, J.-F., Druillole, F., Engelen, J., Favard, S., Feinstein, F., Ferry, S., Festy, D., Fopma, J., Fuda, J.-L., Gallone, J.-M., Giacomelli, G., Girard, N., Goret, P., Gournay, J.-F., Hallewell, G., Hartmann, B., Heijboer, A., Hello, Y., Hernández-Rey, J.J., Herrouin, G., Hößl, J., Hoffmann, C., Hubbard, J.R., Jaquet, M., de Jong, M., Jouvenot, F., Kappes, A., Karg, T., Karkar, S., Karolak, M., Katz, U., Keller, P., Kooijman, P., Korolkova, E.V., Kouchner, A., Kretschmer, W., Kudryavtsev, V.A., Lafoux, H., Lagier, P., Lamare, P., Languillat, J.-C., Laubier, L., Legou, T., Guen, Y. Le, Provost, H. Le, Van Suu, A. Le, Nigro, L. Lo, Presti, D. Lo, Loucatos, S., Louis, F., Lyashuk, V., Magnier, P., Marcelin, M., Margiotta, A., Maron, C., Massol, A., Mazéas, F., Mazeau, B., Mazure, A., McMillan, J.E., Michel, J.-L., Millot, C., Milovanovic, A., Montanet, F., Montaruli, T., Morel, J.-P., Moscoso, L., Nezri, E., Niess, V., Nooren, G.J., Ogden, P., Olivetto, C., Palanque-Delabrouille, N., Payre, P., Petta, C., Pineau, J.-P., Poinsignon, J., Popa, V., Potheau, R., Pradier, T., Racca, C., Randazzo, N., Real, D., van Rens, B.A.P., Réthoré, F., Ripani, M., Roca-Blay, V., Romeyer, A., Rollin, J.-F., Romita, M., Rose, H.J., Rostovtsev, A., Ruppi, M., Russo, G.V., Sacquin, Y., Saouter, S., Schuller, J.-P., Schuster, W., Sokalski, I., Suvorova, O., Spooner, N.J.C., Spurio, M., Stolarczyk, T., Stubert, D., Taiuti, M., Thompson, L.F., Tilav, S., Usik, A., Valdy, P., Vallage, B., Vaudaine, G., Vernin, P., Virieux, J., Vladimirsky, E., de Vries, G., de Witt Huberts, P., de Wolf, E., Zaborov, D., Zaccone, H., Zakharov, V., Zavatarelli, S., de Zornoza, J.D., and Zúñiga, J.

Published
2005
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28. Study of large hemispherical photomultiplier tubes for the ANTARES neutrino telescope

Author

Aguilar, J.A., Albert, A., Ameli, F., Amram, P., Anghinolfi, M., Anton, G., Anvar, S., Ardellier-Desages, F.E., Aslanides, E., Aubert, J.-J., Bailey, D., Basa, S., Battaglieri, M., Becherini, Y., Bellotti, R., Beltramelli, J., Bertin, V., Billault, M., Blaes, R., Blanc, F., de Botton, N., Boulesteix, J., Bouwhuis, M.C., Brooks, C.B., Bradbury, S.M., Bruijn, R., Brunner, J., Burgio, G.F., Cafagna, F., Calzas, A., Capone, A., Caponetto, L., Carmona, E., Carr, J., Cartwright, S.L., Castorina, E., Cavasinni, V., Cecchini, S., Charvis, P., Circella, M., Colnard, C., Compère, C., Coniglione, R., Cooper, S., Coyle, P., Cuneo, S., Damy, G., van Dantzig, R., Deschamps, A., De Marzo, C., Denans, D., Destelle, J.-J., De Vita, R., Dinkelspiler, B., Distefano, C., Drogou, J.-F., Druillole, F., Engelen, J., Ernenwein, J.-P., Falchini, E., Favard, S., Feinstein, F., Ferry, S., Festy, D., Flaminio, V., Fopma, J., Fuda, J.-L., Gallone, J.-M., Giacomelli, G., Girard, N., Goret, P., Graf, K., Hallewell, G., Hartmann, B., Heijboer, A., Hello, Y., Hernández-Rey, J.J., Herrouin, G., Hößl, J., Hoffmann, C., Hubbard, J.R., Jaquet, M., de Jong, M., Jouvenot, F., Kappes, A., Karg, T., Karkar, S., Karolak, M., Katz, U., Keller, P., Kooijman, P., Korolkova, E.V., Kouchner, A., Kretschmer, W., Kuch, S., Kudryavtsev, V.A., Lafoux, H., Lagier, P., Lahmann, R., Lamare, P., Languillat, J.-C., Laschinsky, H., Laubier, L., Legou, T., Le Guen, Y., Le Provost, H., Le Van Suu, A., Lo Nigro, L., Lo Presti, D., Loucatos, S., Louis, F., Lyashuk, V., Marcelin, M., Margiotta, A., Maron, C., Massol, A., Masullo, R., Mazéas, F., Mazure, A., McMillan, J.E., Migneco, E., Millot, C., Milovanovic, A., Montanet, F., Montaruli, T., Morel, J.-P., Morganti, M., Moscoso, L., Musumeci, M., Naumann, C., Naumann-Godo, M., Nezri, E., Niess, V., Nooren, G.J., Ogden, P., Olivetto, C., Palanque-Delabrouille, N., Papaleo, R., Payre, P., Petta, C., Piattelli, P., Pineau, J.-P., Poinsignon, J., Popa, V., Potheau, R., Pradier, T., Racca, C., Raia, G., Randazzo, N., Real, D., van Rens, B.A.P., Réthoré, F., Riccobene, G., Rigaud, V., Ripani, M., Roca-Blay, V., Rolin, J.-F., Romita, M., Rose, H.J., Rostovtsev, A., Ruppi, M., Russo, G.V., Sacquin, Y., Salesa, F., Salomon, K., Saouter, S., Sapienza, P., Shanidze, R., Schuller, J.-P., Schuster, W., Sokalski, I., Spurio, M., Stolarczyk, T., Stubert, D., Taiuti, M., Thompson, L.F., Tilav, S., Valdy, P., Valente, V., Vallage, B., Vernin, P., Virieux, J., de Vries, G., de Witt Huberts, P., de Wolf, E., Zaborov, D., Zaccone, H., Zakharov, V., Zornoza, J.D., and Zúñiga, J.

Published
2005
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30. Slope tomography based on eikonal solvers and the adjoint-state method

Author

Tavakoli F., B., Operto, S., Ribodetti, A., Virieux, J., Géoazur (GEOAZUR 7329), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])

Subjects
Mathematical optimization, Seismic tomography, 010504 meteorology & atmospheric sciences, Computer science, Geophysical imaging, Eikonal equation, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Inversion (meteorology), Solver, 010502 geochemistry & geophysics, System of linear equations, 01 natural sciences, Geophysics, Numerical modelling, Geochemistry and Petrology, Adjoint state method, Tomography, Inverse theory, Algorithm, 0105 earth and related environmental sciences
Abstract

International audience; Velocity macromodel building is a crucial step in the seismic imaging workflow as it provides the necessary background model for migration or full waveform inversion. In this study, we present a new formulation of stereotomography that can handle more efficiently long-offset acquisition, complex geological structures and large-scale data sets. Stereotomography is a slope tomographic method based upon a semi-automatic picking of local coherent events. Each local coherent event, characterized by its two-way traveltime and two slopes in common-shot and common-receiver gathers, is tied to a scatterer or a reflector segment in the subsurface. Ray tracing provides a natural forward engine to compute traveltime and slopes but can suffer from non-uniform ray sampling in presence of complex media and long-offset acquisitions. Moreover, most implementations of stereotomography explicitly build a sensitivity matrix, leading to the resolution of large systems of linear equations, which can be cumbersome when large-scale data sets are considered. Overcoming these issues comes with a new matrix-free formulation of stereotomography: a factored eikonal solver based on the fast sweeping method to compute first-arrival traveltimes and an adjoint-state formulation to compute the gradient of the misfit function. By solving eikonal equation from sources and receivers, we make the computational cost proportional to the number of sources and receivers while it is independent of picked events density in each shot and receiver gather. The model space involves the subsurface velocities and the scatterer coordinates, while the dips of the reflector segments are implicitly represented by the spatial support of the adjoint sources and are updated through the joint localization of nearby scatterers. We present an application on the complex Marmousi model for a towed-streamer acquisition and a realistic distribution of local events. We show that the estimated model, built without any prior knowledge of the velocities, provides a reliable initial model for frequency-domain FWI of long-offset data for a starting frequency of 4 Hz, although some artefacts at the reservoir level result from a deficit of illumination. This formulation of slope tomography provides a computationally efficient alternative to waveform inversion method such as reflection waveform inversion or differential-semblance optimization to build an initial model for pre-stack depth migration and conventional FWI.

Published
2017
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