Consulta: subjectFacets:"Surface waves and free oscillations"
Registros recuperados: 6
Data/hora: 17/06/2024 02:18:56

Modelling secondary microseismic noise by normal mode summation
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Gualtieri, L.; Stutzmann, E.; Capdeville, Y.; Ardhuin, Fabrice; Schimmel, M.; Mangeney, A.; Morelli, A.
Secondary microseisms recorded by seismic stations are generated in the ocean by the interaction of ocean gravity waves. We present here the theory for modelling secondary microseismic noise by normal mode summation. We show that the noise sources can be modelled by vertical forces and how to derive them from a realistic ocean wave model. We then show how to compute bathymetry excitation effect in a realistic earth model by using normal modes and a comparison with Longuet-Higgins approach. The strongest excitation areas in the oceans depends on the bathymetry and period and are different for each seismic mode. Seismic noise is then modelled by normal mode summation considering varying bathymetry. We derive an attenuation model that enables to fit well the...
Tipo: Text
Palavras-chave: Surface waves and free oscillations; Seismic attenuation; Theoretical seismology; Wave propagation.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00146/25703/24020.pdf

Crustal and uppermost mantle structure variation beneath La Réunion hotspot track
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Fontaine, Fabrice R.; Barruol, Guilhem; Tkalcic, Hrvoje; Woelbern, Ingo; Ruempker, Georg; Bodin, Thomas; Haugmard, Meric.
The Piton de la Fournaise basaltic volcano, on La Réunion Island in the western Indian Ocean, is one of the most active volcanoes in the world. This volcano is classically considered as the surface expression of an upwelling mantle plume and its activity is continuously monitored, providing detailed information on its superficial dynamics and on the edifice structure. Deeper crustal and upper mantle structure under La Réunion Island is surprisingly poorly constrained, motivating this study. We used receiver function techniques to determine a shear wave velocity profile through the crust and uppermost mantle beneath La Réunion, but also at other seismic stations located on the hotspot track, to investigate the plume and lithosphere interaction and its...
Tipo: Text
Palavras-chave: Surface waves and free oscillations; Oceanic hotspots and intraplate volcanism; Hotspots; Crustal structure; Indian Ocean.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00287/39830/38352.pdf

Modelling long-term seismic noise in various environments
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Stutzmann, E.; Ardhuin, Fabrice; Schimmel, M.; Mangeney, A.; Patau, G.
The strongest seismic noise, called secondary microseisms, is generated by ocean wave interactions and we model this noise using the theory of Longuet-Higgins generalized to random ocean gravity waves. Noise sources are computed with an ocean wave model that takes into account coastal reflections. Variations of the source locations are consistent with seasonal variations of seismic noise spectra. Noise spectra are modelled over many years for stations representative of various environments such as continent, island and polar area to constrain, for each environment, the parameters involved in the modelling. For each station, we quantify the trade-off between ocean wave coastal reflection and seismic wave attenuation that both affect the amplitude of the...
Tipo: Text
Palavras-chave: Surface waves and free oscillations; Theoretical seismology; Wave propagation.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00107/21839/19436.pdf

Arrival angles of teleseismic fundamental mode Rayleigh waves across the AlpArray
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Kolinsky, Petr; Bokelmann, Goetz; Hetenyi, Gyorgy; Abreu, Rafael; Allegretti, Ivo; Apoloner, Maria-theresia; Aubert, Coralie; Besancon, Simon; Bes De Berc, Maxime; Bokel-mann, Gotz; 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; Groschl, 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; Kolinsky, Petr; Kopp, Heidrun; Korn, Michael; Kotek, Josef; Kuhne, Lothar; Kuk, Kreso; Lange, Dietrich; Loos, Jurgen; 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.
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...
Tipo: Text
Palavras-chave: Structure of the Earth; Europe; Time-series analysis; Surface waves and free oscillations; Wave propagation; Wave scattering and diffraction.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00690/80172/83241.pdf

Ambient noise Rayleigh wave tomography across the Madagascar island
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Adimah, N I; Padhy, S.
The unusual complex lithospheric structure of Madagascar is a product of a number of important geological events, including: the Pan-African Orogeny, episodes of Late Cenozoic intraplate volcanism and several phases of deformation and metamorphism. Despite this rich history, its detailed crustal structure remains largely underexplored. Here, we take advantage of the recently obtained data set of the RHUM-RUM (Réunion Hotspot and Upper Mantle–Réunions Unterer Mantel) seismological experiment, in addition to previously available data sets to generate the first Rayleigh wave group velocity maps across the entire island at periods between 5 and 30 s using the ambient noise tomography technique. Prior to preliminary data preparation, data from Ocean Bottom...
Tipo: Text
Palavras-chave: Seismic tomography; Africa; Crustal structure; Surface waves and free oscillations; Seismic noise.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00600/71184/69539.pdf

Sources of secondary microseisms in the Indian Ocean
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Davy, C.; Stutzmann, E.; Barruol, G.; Fontaine, F. R.; Schimmel, M.
Ocean waves activity is a major source of microvibrations that travel through the solid Earth, known as microseismic noise and recorded worldwide by broadband seismometers. Analysis of microseismic noise in continuous seismic records can be used to investigate noise sources in the oceans such as storms, and their variations in space and time, making possible the regional and global-scale monitoring of the wave climate. In order to complete the knowledge of the Atlantic and Pacific oceans microseismic noise sources, we analyse 1 yr of continuous data recorded by permanent seismic stations located in the Indian Ocean basin. We primarily focus on secondary microseisms (SM) that are dominated by Rayleigh waves between 6 and 11 s of period. Continuous...
Tipo: Text
Palavras-chave: Surface waves and free oscillations; Indian Ocean.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00287/39825/38335.pdf