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4 results on '"D'Alema, Ezio"'

1. Evidence for radial anisotropy in the lower crust of the Apennines from Bayesian ambient noise tomography in Europe

Author

Alder, C., Debayle, E., Bodin, T., Paul, A., Stehly, L., Pedersen, H., Allegretti, Ivo, Apoloner, Maria-Theresia, Aubert, Coralie, Besançon, Simon, Bés de Berc, Maxime, Abreu, Rafael, Brunel, Didier, Capello, Marco, Čarman, Martina, Cavaliere, Adriano, Chéze, Jérôme, Chiarabba, Claudio, Clinton, John, Cougoulat, Glenn, C. Crawford, Wayne, Cristiano, Luigia, Czifra, Tibor, D’Alema, Ezio, Danesi, Stefania, Daniel, Romuald, Dannowski, Anke, Dasović, Iva, Deschamps, Anne, Dessa, Jean-Xavier, Doubre, Cécile, Egdorf, Sven, Fiket, Tomislav, Fischer, Kasper, Friederich, Wolfgang, Fuchs, Florian, Funke, Sigward, Giardini, Domenico, Govoni, Aladino, Gráczer, Zoltán, Gröschl, Gidera, Heimers, Stefan, Heit, Ben, Herak, Davorka, Herak, Marijan, Huber, Johann, Jarić, Dejan, Jedlička, Petr, Jia, Yan, Jund, Hélène, Kissling, Edi, Klingen, Stefan, Klotz, Bernhard, Kolínský, Petr, Kopp, Heidrun, Korn, Michael, Kotek, Josef, Kühne, Lothar, Kuk, Krešo, Lange, Dietrich, Loos, Jürgen, Lovati, Sara, Malengros, Deny, Margheriti, Lucia, Maron, Christophe, Martin, Xavier, Massa, Marco, Mazzarini, Francesco, Meier, Thomas, Métral, Laurent, Molinari, Irene, Moretti, Milena, Nardi, Anna, Pahor, Jurij, Paul, Anne, Péquegnat, Catherine, Petersen, Daniel, Pesaresi, Damiano, Piccinini, Davide, Piromallo, Claudia, Plenefisch, Thomas, Plomerová, Jaroslava, Pondrelli, Silvia, Prevolnik, Snježan, Racine, Roman, Régnier, Marc, Reiss, Miriam, Ritter, Joachim, Rümpker, Georg, Salimbeni, Simone, Santulin, Marco, Scherer, Werner, Schippkus, Sven, Schulte-Kortnack, Detlef, Šipka, Vesna, Solarino, Stefano, Spallarossa, Daniele, Spieker, Kathrin, Stipčević, Josip, Strollo, Angelo, Süle, Bálint, Szanyi, Gyöngyvér, Szűcs, Eszter, Thomas, Christine, Thorwart, Martin, Tilmann, Frederik, Ueding, Stefan, Vallocchia, Massimiliano, Vecsey, Luděk, Voigt, René, Wassermann, Joachim, Wéber, Zoltán, Weidle, Christian, Wesztergom, Viktor, Weyland, Gauthier, Wiemer, Stefan, Wolf, Felix Noah, Wolyniec, David, Zieke, Thomas, Živčić, Mladen, Žlebčíková, Helena, Hein, Gerrit, Bianchi, Irene, Bokelmann, Götz, Hetényi, György, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre (ISTerre), 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 Gustave Eiffel-Université Grenoble Alpes (UGA), ANR-15-CE31-0015,AlpArray-FR,Voir et comprendre les Alpes en 3D, de la croûte au manteau(2015), Université de Lyon, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)

Subjects
Seismic anisotropy, 010504 meteorology & atmospheric sciences, Seismic noise, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Bayesian probability, Ambient noise level, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, Geochemistry and Petrology, Anisotropy, 0105 earth and related environmental sciences, Seismic tomography, Crust, Europe, Geophysics, 13. Climate action, Tomography, Astrophysics::Earth and Planetary Astrophysics, Surface waves and free oscillations, Seismology, Geology
Abstract

SUMMARYProbing seismic anisotropy of the lithosphere provides valuable clues on the fabric of rocks. We present a 3-D probabilistic model of shear wave velocity and radial anisotropy of the crust and uppermost mantle of Europe, focusing on the mountain belts of the Alps and Apennines. The model is built from Love and Rayleigh dispersion curves in the period range 5–149 s. Data are extracted from seismic ambient noise recorded at 1521 broad-band stations, including the AlpArray network. The dispersion curves are first combined in a linearized least squares inversion to obtain 2-D maps of group velocity at each period. Love and Rayleigh maps are then jointly inverted at depth for shear wave velocity and radial anisotropy using a Bayesian Monte Carlo scheme that accounts for the trade-off between radial anisotropy and horizontal layering. The isotropic part of our model is consistent with previous studies. However, our anisotropy maps differ from previous large scale studies that suggested the presence of significant radial anisotropy everywhere in the European crust and shallow upper mantle. We observe instead that radial anisotropy is mostly localized beneath the Apennines while most of the remaining European crust and shallow upper mantle is isotropic. We attribute this difference to trade-offs between radial anisotropy and thin (hectometric) layering in previous studies based on least-squares inversions and long period data (>30 s). In contrast, our approach involves a massive data set of short period measurements and a Bayesian inversion that accounts for thin layering. The positive radial anisotropy (VSH > VSV) observed in the lower crust of the Apennines cannot result from thin layering. We rather attribute it to ductile horizontal flow in response to the recent and present-day extension in the region.

Published
2021
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2. Arrival angles of teleseismic fundamental mode Rayleigh waves across the AlpArray

Author

Kolinsky, Petr, Bokelmann, Götz, Hetenyi, Gyorgy, Abreu, Rafael, Allegretti, Ivo, Apoloner, Maria-Theresia, Aubert, Coralie, Besancon, Simon, Bes De Berc, Maxime, Bokelmann, Goetz, Brunel, Didier, Capello, Marco, Carman, Martina, Cavaliere, Adriano, Cheze, Jerome, Chiarabba, Claudio, Clinton, John, Cougoulat, Glenn, Grawford, Wayne C., Cristiano, Luigia, Czifra, Tibor, D'Alema, Ezio, Danesi, Stefania, Daniel, Romuald, Dannowski, Anke, Dasovic, Iva, Deschamps, Anne, Dessa, Jean-Xavier, Doubre, Cecile, Egdorf, Sven, Fiket, Tomislav, Fischer, Kasper, Friederich, Wolfgang, Fuchs, Florian, Funke, Sigward, Giardini, Domenico, Govoni, Aladino, Graczer, Zoltan, Groeschl, Gidera, Heimers, Stefan, Heit, Ben, Herak, Davorka, Herak, Marijan, Huber, Johann, Jaric, Dejan, Jedlicka, Petr, Jia, Yan, Jund, Helene, Kissling, Edi, Klingen, Stefan, Klotz, Bernhard, Kopp, Heidrun, Korn, Michael, Kotek, Josef, Kuhne, Lothar, Kuk, Kreso, Lange, Dietrich, Loos, Jürgen, Lovati, Sara, Malengros, Deny, Margheriti, Lucia, Maron, Christophe, Martin, Xavier, Massa, Marco, Mazzarini, Francesco, Meier, Thomas, Metral, Laurent, Molinari, Irene, Moretti, Milena, Nardi, Anna, Pahor, Jurij, Paul, Anne, Pequegnat, Catherine, Petersen, Daniel, Pesaresi, Damiano, Piccinini, Davide, Piromallo, Claudia, Plenefisch, Thomas, Plomerova, Jaroslava, Pondrelli, Silvia, Prevolnik, Snjezan, Racine, Roman, Regnier, Marc, Reiss, Miriam, Ritter, Joachim, Rumpker, Georg, Salimbeni, Simone, Santulin, Marco, Scherer, Werner, Schippkus, Sven, Schulte-Kortnack, Detlef, Sipka, Vesna, Solarino, Stefano, Spallarossa, Daniele, Spieker, Kathrin, Stipcevic, Josip, Strollo, Angelo, Sule, Balint, Szanyi, Gyongyver, Szucs, Eszter, Thomas, Christine, Thorwart, Martin, Tilmann, Frederik, Ueding, Stefan, Vallocchia, Massimiliano, Vecsey, Ludek, Voigt, Rene, Wassermann, Joachim, Weber, Zoltan, Weidle, Christian, Wesztergom, Viktor, Weyland, Gauthier, Wiemer, Stefan, Wolf, Felix, Wolyniec, David, Zieke, Thomas, Zivcic, Mladen, Zlebcikova, Helena, Institut für Meteorologie und Geophysik [Wien] (IMGW), Universität Wien, Austrian Science Fund (FWF)through project P 26391–AlpArray Austria and P 30707–AlpArrayAustria 2. The Python Toolbox ObsPy by Beyreuther et al. (2010)was used for data pre-processing. Maps were plotted using GenericMapping Tools by Wessel et al. (2013)., and University of Vienna [Vienna]

Subjects
Beamforming, Wave propagation, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Earth structure, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, symbols.namesake, Geochemistry and Petrology, Time-series analysis, Wave scattering and diffraction, Rayleigh wave, 0105 earth and related environmental sciences, Anomaly (natural sciences), Geodesy, Europe, Geophysics, Phase correlation, symbols, engineering, Structure of the Earth, Surface waves and free oscillations, Geology, Earthquake location, Gaussian beam
Abstract

International audience; The dense AlpArray network allows studying seismic wave propagation with high spatial resolution. Here we introduce an array approach to measure arrival angles of teleseismic Rayleigh waves. The approach combines the advantages of phase correlation as in the two-station method with array beamforming to obtain the phase-velocity vector. 20 earthquakes from the first two years of the AlpArray project are selected, and spatial patterns of arrival-angle deviations across the AlpArray are shown in maps, depending on period and earthquake location. The cause of these intriguing spatial patterns is discussed. A simple wave-propagation modelling example using an isolated anomaly and a Gaussian beam solution suggests that much of the complexity can be explained as a result of wave interference after passing a structural anomaly along the wave paths. This indicates that arrival-angle information constitutes useful additional information on the Earth structure, beyond what is currently used in inversions.

Published
2019
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3. Ambient-noise tomography of the wider Vienna Basin region

Author

Schippkus, Sven, Zigone, Dimitri, Bokelmann, Götz, Hetenyi, György, Abreu, Rafael, Allegretti, Ivo, Apoloner, Maria-Theresia, Aubert, Coralie, Besancon, Simon, Bes de Berc, Maxime, Brunel, Didier, Capello, Marco, Carman, Martina, Cavaliere, Adriano, Cheze, Jerome, Chiarabba, Claudio, Clinton, John, Cougoulat, Glenn, Crawford, Wayne C., Cristiano, Luigia, Czifra, Tibor, D'Alema, Ezio, Danesi, Stefania, Daniel, Romuald, Dannowski, Anke, Dasovic, Iva, Deschamps, Anne, Dessa, Jean-Xavier, Doubre, Cecile, Egdorf, Sven, Fiket, Tomislav, Fischer, Kasper, Friederich, Wolfgang, Fuchs, Florian, Funke, Sigward, Giardini, Domenico, Govoni, Aladino, Graczer, Zoltan, Gröschl, Gidera, Heimers, Stefan, Heit, Ben, Herak, Davorka, Huber, Johann, Jaric, Dejan, Jedlicka, Petr, Jia, Yan, Jund, Helene, Kissling, Edi, Klingen, Stefan, Klotz, Bernhard, Kolinsky, Petr, Kopp, Heidrun, Korn, Michael, Kotek, Josef, Kühne, Lothar, Kuk, Kreso, Lange, Dietrich, Loos, Jürgen, Lovati, Sara, Malengros, Deny, Margheriti, Lucia, Maron, Christophe, Martin, Xavier, Massa, Marco, Mazzarini, Francesco, Meier, Thomas, Metral, Laurent, Molinari, Irene, Moretti, Milena, Munzarova, Helena, Nardi, Anna, Pahor, Jurij, Paul, Anne, Pequegnat, Catherine, Petersen, Daniel, Pesaresi, Damiano, Piccinini, Davide, Piromallo, Claudia, Plenefisch, Thomas, Plomerova, Jaroslava, Pondrelli, Silvia, Prevolnik, Snjezan, Racine, Roman, Regnier, Marc, Reiss, Miriam, Ritter, Joachim, Rümpker, Georg, Salimbeni, Simone, Santulin, Marco, Scherer, Werner, Schulte-Kortnack, Detlef, Sipka, Vesna, Solarino, Stefano, Spallarossa, Daniele, Spieker, Kathrin, Stipcevic, Josip, Strollo, Angelo, Süle, Balint, Szanyi, Gyöngyver, Szücs, Eszter, Thomas, Christine, Thorwart, Martin, Tilmann, Frederik, Ueding, Stefan, Vallocchia, Massimiliano, Vecsey, Ludek, Voigt, Rene, Wassermann, Joachim, Weber, Zoltan, Weidle, Christian, Wesztergom, Viktor, Weyland, Gauthier, Wiemer, Stefan, Wolf, Felix Noah, Wolyniec, David, Zieke, Thomas, Zivcic, Mladen, Institut für Meteorologie und Geophysik [Wien] (IMGW), Universität Wien, Sismologie (IPGS) (IPGS-Sismologie), Institut de physique du globe de Strasbourg (IPGS), and Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Seismic noise, Wave propagation, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Seismic interferometry, Fault (geology), Crustal structure, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, symbols.namesake, Geochemistry and Petrology, Rayleigh wave, Dispersion (water waves), Crustal imaging, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Seismic tomography, Tectonics, Geophysics, symbols, Seismology, Geology
Abstract

International audience; We present a new 3-D shear-velocity model for the top 30 km of the crust in the wider Vienna Basin region based on surface waves extracted from ambient-noise cross-correlations. We use continuous seismic records of 63 broad-band stations of the AlpArray project to retrieve interstation Green's functions from ambient-noise cross-correlations in the period range from 5 to 25 s. From these Green's functions, we measure Rayleigh group traveltimes, utilizing all four components of the cross-correlation tensor, which are associated with Rayleigh waves (ZZ, RR, RZ and ZR), to exploit multiple measurements per station pair. A set of selection criteria is applied to ensure that we use high-quality recordings of fundamental Rayleigh modes. We regionalize the interstation group velocities in a 5 km × 5 km grid with an average path density of ∼20 paths per cell. From the resulting group-velocity maps, we extract local 1-D dispersion curves for each cell and invert all cells independently to retrieve the crustal shear-velocity structure of the study area. The resulting model provides a previously unachieved lateral resolution of seismic velocities in the region of ∼15 km. As major features, we image the Vienna Basin and Little Hungarian Plain as low-velocity anomalies, and the Bohemian Massif with high velocities. The edges of these features are marked with prominent velocity contrasts correlated with faults, such as the Alpine Front and Vienna Basin transfer fault system. The observed structures correlate well with surface geology, gravitational anomalies and the few known crystalline basement depths from boreholes. For depths larger than those reached by boreholes, the new model allows new insight into the complex structure of the Vienna Basin and surrounding areas, including deep low-velocity zones, which we image with previously unachieved detail. This model may be used in the future to interpret the deeper structures and tectonic evolution of the wider Vienna Basin region, evaluate natural resources, model wave propagation and improve earthquake locations, among others.

Published
2018
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4. Evaluation of the local site effects in the upper and middle Aterno valley

Author

Ameri, Gabriele, P, Augliera, Azzara, Riccardo, F, Bergamaschi, Bertrand, Etienne, Paola, Bordoni, F, Cara, R, Cogliano, Cultrera, Giovanna, d'Alema, Ezio, Di Giacomo, Domenico, Di Giulio, Giuseppe, Duval, Anne-Marie, Fodarella, Antonio, Franceschina, Gianlorenzo, Gallipoli, Maria, P, Harabaglia, Ladina, C., Lovati, Sara, Sobiesiak, Monika, and Duval, Anne-Marie

Subjects
[SDU.STU.GP] Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
Abstract

In the months following the April 6th, 2009, L’Aquila earthquake, several Italian and foreign research institutions installed dozens of seismic stations to monitor more than 100 localities with the aim of studying the local site effects in the epicentral area (upper and middle Aterno valley). The stations (accelerometers and velocimeters) have been deployed inside or very close to the inhabited areas. Among the investigated sites there are Onna, where almost the totality of the buildings collapsed, and the historic centre of L’Aquila, both towns suffering many casualties. The preliminary results for the examined sites show an extreme variability of ground motion and significant amplification for the most damaged localities.

Published
2009

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