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| Registros recuperados: 31 | |
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| 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 |
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| 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 |
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| Bertrand, E; Deschamps, A; Virieux, J. |
| An investigation of the teleseismic P -wave coda is performed using the single-scattering approximation. The method allows one to image short-wavelength scale (less than or equal to2 km) velocity and density heterogeneities and structures that are barely detected by traveltime tomography. Source effects are removed by using receiver functions for data interpretation, but the amplitude (especially the sign of the signal) is synthesized. Both broad-band seismological stations in the southwestern Alps (France) and Campanian plain (Italy) are used for the illustration of the proposed method. Because of the large aperture of our arrays, laterally small-scale heterogeneities are difficult to image and we must assume lateral continuity of the detectable... |
| Tipo: Text |
Palavras-chave: Body waves; Broad-band; Crustal structure; Moho discontinuity; P-to-S conversions; Scattering; Waveform analysis. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00466/57762/60036.pdf |
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| Klingelhoefer, Frauke; Lafoy, Y; Collot, Julien; Cosquer, Emmanuel; Geli, Louis; Nouze, Herve; Vially, R. |
| [1] During the Zoneco 11 marine geophysical survey (September 2004), two deep reflection seismic profiles recorded by ocean bottom seismometers were acquired in the offshore domain west of New Caledonia. The northern profile crosses the New Caledonia Basin, the Fairway Ridge, the Fairway Basin, and the Lord Howe Rise. The southern profile crosses the Norfolk Rise south of New Caledonia, the New Caledonia Basin, the Fairway Ridge and Basin, and ends at the foot of Lord Howe Rise. On the northern profile the Lord Howe Rise has a crustal thickness of 23 km and exhibits seismic velocities and velocity gradients characteristic of continental crust. The crust thins to 12-15 km in the neighboring Fairway Basin, which is interpreted to be of thinned continental... |
| Tipo: Text |
Palavras-chave: Crustal structure; SW Pacific; Wide angle seismic. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3543.pdf |
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| Klingelhoefer, Frauke; Edwards, R; Hobbs, R; England, R. |
| [1] Two wide-angle seismic lines located in the northern Rockall Trough were acquired in May 2000. One line ( line E) crosses the trough from the continental shelf off Lewis to normal oceanic crust west of Lousy Bank in NW-SE direction. The other line ( line D) intersects with line E, crosses the Wyville-Thomson Ridge in a SW-NE direction and ends in the Faeroe-Shetland Basin. Sonobuoy data and expanding spread profiles acquired in the same area have been remodeled. Analysis of the seismic data using travel times and amplitudes reveals an up to 5 km thick sedimentary basin including an up to 1.5 km thick basaltic layer which is present in most of the trough. Further conclusions of this study are that the Rockall Trough is underlain by highly stretched... |
| Tipo: Text |
Palavras-chave: Crustal structure; Wide angle seismics; Rockall Trough. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-881.pdf |
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| Moulin, Maryline; Klingelhoefer, Frauke; Afilhado, Alexandra; Aslanian, Daniel; Schnurle, Philippe; Nouze, Herve; Rabineau, Marina; Beslier, Marie-odile; Feld, Aurelie. |
| The conjugate margins system of the Gulf of Lion and West Sardinia (GLWS) represents a unique natural laboratory for addressing fundamental questions about rifting due to its landlocked situation, its youth, its thick sedimentary layers, including prominent palaeo-marker such as the MSC event, and the amount of available data and multidisciplinary studies. The main goals of the SARDINIA experiment, were to (i) investigate the deep structure of the entire system within the two conjugate margins: the Gulf of Lion and West Sardinia, (ii) characterize the nature of the crust, and (iii) define the geometry of the basin and provide important constrains on its genesis. This paper presents the results of P-wave velocity modelling on three coincident near-vertical... |
| Tipo: Text |
Palavras-chave: Marge continentale passive; Structure crustale; Réfraction; Golfe du Lion; Croûte océanique; Domaine transitionnel; Continental passive margin; Crustal structure; Wide-angle seismic; Gulf of Lion; Oceanic crust; Transitional domain. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00283/39422/38269.pdf |
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| Aidi, Chafik; Beslier, Marie-odile; Yelles-chaouche, Abdel Karim; Klingelhoefer, Frauke; Bracene, Rabah; Galve, Audrey; Bounif, Abdallah; Schenini, Laure; Hamai, Lamine; Schnurle, Philippe; Djellit, Hamou; Sage, Francoise; Charvis, Philippe; Deverchere, Jacques. |
| During the Algerian-French SPIRAL survey aimed at investigating the deep structure of the Algerian margin and basin, two coincident wide-angle and reflection seismic profiles were acquired in central Algeria, offshore Greater Kabylia, together with gravimetric, bathymetric and magnetic data. This ~260 km-long offshore-onshore profile spans the Balearic basin, the central Algerian margin and the Greater Kabylia block up to the southward limit of the internal zones onshore. Results are obtained from modeling and interpretation of the combined data sets. The Algerian basin offshore Greater Kabylia is floored by a thin oceanic crust (~4 km) with P-wave velocities ranging between 5.2 and 6.8 km/s. In the northern Hannibal High region, the atypical 3-layer... |
| Tipo: Text |
Palavras-chave: Mediterranean Sea; Algerian margin; Crustal structure; Tectonic inversion; Post-accretion magmatism; Deep seismics. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00425/53677/54519.pdf |
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| Evain, Mikael; Afilhado, A.; Rigoti, C.; Loureiro, Afonso; Alves, D.; Klingelhoefer, Frauke; Schnurle, Philippe; Feld, Aurelie; Fuck, R.; Soares, J.; De Lima, M. Vinicius; Corela, C.; Matias, L.; Benabdellouahed, Massinissa; Baltzer, Agnes; Rabineau, Marina; Viana, A.; Moulin, Maryline; Aslanian, Daniel. |
| The structure and nature of the crust underlying the Santos Basin-São Paulo Plateau System (SSPS), in the SE Brazilian margin, are discussed based on five wide-angle seismic profiles acquired during the Santos Basin (SanBa) experiment in 2011. Velocity models allow us to precisely divide the SSPS in six domains from unthinned continental crust (Domain CC) to normal oceanic crust (Domain OC). A seventh domain (Domain D), a triangular shape region in the SE of the SSPS, is discussed by Klingelhoefer et al. (2014). Beneath the continental shelf, a ~100 km wide necking zone (Domain N) is imaged where the continental crust thins abruptly from ~40 km to less than 15 km. Toward the ocean, most of the SSPS (Domains A and C) shows velocity ranges, velocity... |
| Tipo: Text |
Palavras-chave: Santos Basin; SAo Paulo Plateau; Crustal structure; Wide-angle seismic. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00276/38715/37232.pdf |
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| Moulin, Maryline; Aslanian, Daniel; Olivet, Jean-louis; Contrucci, Isabelle; Matias, Luis; Geli, Louis; Klingelhoefer, Frauke; Nouze, Herve; Rehault, Jean Pierre; Unternehr, Patrick. |
| Deep penetration multichannel reflection and Ocean Bottom Seismometer wide-angle seismic data from the CongoAngola margin were collected in 2000 during the ZaïAngo cruise. These data help constrain the deep structure of the continental margin, the geometry of the pre-salt sediment layers and the geometry of the Aptian salt layer. Dating the deposition of the salt relative to the chronology of the margin formation is an issue of fundamental importance for reconstructing the evolution of the margin and for the understanding of the crustal thinning processes. The data show that the crust thins abruptly, from a 3040 km thickness to less than 10 km, over a lateral distance of less than 50 km. The transitional domain is a 180-km-wide basin. The pre-salt sediment... |
| Tipo: Text |
Palavras-chave: Deep seismic reflection and refraction; Sub salt imaging; Transitional domain; Crustal structure; Non volcanic passive continental margin. |
| Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/2005/publication-349.pdf |
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| Dellong, David; Klingelhoefer, Frauke; Dannowski, Anke; Kopp, Heidrun; Murphy, Shane; Graindorge, David; Margheriti, Lucia; Moretti, Milena; Barreca, Giovanni; Scarfì, Luciano; Polonia, Alina; Gutscher, Marc-andre. |
| The Calabrian subduction zone is one of the narrowest arcs on Earth and a key area to understand the geodynamic evolution of the Mediterranean and other marginal seas. Here in the Ionian Sea, the African plate subducts beneath Eurasia. Imaging the boundary between the downgoing slab and the upper plate along the Calabrian subduction zone is important for assessing the potential of the subduction zone to generate mega‐thrust earthquakes and was the main objective of this study. Here we present and analyze the results from a 380 km long, wide‐angle seismic profile spanning the complete subduction zone, from the deep Ionian Basin and the accretionary wedge to NE Sicily, with additional constraints offered by 3‐D Gravity modeling and the analysis of earthquake... |
| Tipo: Text |
Palavras-chave: Ionian Basin; Wide-angle seismic; Gravity; Crustal structure; Seismicity; Tomography. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00592/70442/68544.pdf |
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| Badji, Rabia; Charvis, Philippe; Bracene, Rabah; Galve, Audrey; Badsi, Madjid; Ribodetti, Alessandra; Benaissa, Zahia; Klingelhoefer, Frauke; Medaouri, Mourad; Beslier, Marie-odile. |
| For the first time, a deep seismic data set acquired in the frame of the Algerian-French SPIRAL program provides new insights regarding the origin of the westernmost Algerian margin and basin. We performed a tomographic inversion of traveltimes along a 100-km-long wide-angle seismic profile shot over 40 ocean bottom seismometers offshore Mostaganem (Northwestern Algeria). The resulting velocity model and multichannel seismic reflection profiles show a thin (3-4 km thick) oceanic crust. The narrow ocean-continent transition (less than 10 km wide) is bounded by vertical faults and surmounted by a narrow almost continuous basin filled with Miocene to Quaternary sediments. This fault system, as well as the faults organized in a negative-flower structure on the... |
| Tipo: Text |
Palavras-chave: Seismic tomography; Continental margins: transform; Crustal structure; Africa; Europe.. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00255/36670/35278.pdf |
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| Loureiro, Afonso; Schnurle, Philippe; Klingelhofer, F.; Afilhado, A.; Pinheiro, Joao Marcelo; Evain, Mikael; Gallais, Flora; Dias, N. A.; Rabineau, Marina; Baltzer, Agnes; Benabdellouahed, Massinissa; Soares, J.; Fuck, R.; Cupertino, J. A.; Viana, A.; Matias, L.; Moulin, Maryline; Aslanian, Daniel; Vinicius Aparecido Gomes De Lima, M.. |
| Twelve combined wide-angle refraction and coincident multi-channel seismic profiles were acquired in the Jequitinhonha-Camamu-Almada, Jacuípe, and Sergipe-Alagoas basins, NE Brazil, during the SALSA experiment in 2014. Profiles SL11 and SL12 image the Jequitinhonha basin, perpendicularly to the coast, with 15 and 11 four-channel ocean-bottom seismometers, respectively. Profile SL10 runs parallel to the coast, crossing profiles SL11 and SL12, imaging the proximal Jequitinhonha and Almada basins with 17 ocean-bottom seismometers. Forward modelling, combined with pre-stack depth migration to increase the horizontal resolution of the velocity models, indicates that sediment thickness varies between 3.3 km and 6.2 km in the distal basin. Crustal thickness at... |
| Tipo: Text |
Palavras-chave: NE Brazil; South Atlantic Ocean; Passive margins; Wide-angle refraction seismic; PSDM; Crustal structure; Cretaceous breakup; Lower continental crust. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00428/53928/55054.pdf |
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| Klingelhoefer, Frauke; Evain, Mikael; Afilhado, A.; Rigoti, Caesar; Loureiro, Afonso; Alves, D.; Lepretre, Angelique; Moulin, Maryline; Schnurle, Philippe; Benabdellouahed, Massinissa; Baltzer, Agnes; Rabineau, Marina; Feld, Aurelie; Viana, A.; Aslanian, Daniel. |
| During the Sanba (Santos basin seismic transect) experiment in 2010–2011, a 380-km-long combined wide-angle and reflection seismic profile has been acquired using 30 ocean-bottom seismometers, a 4.5 km seismic streamer and a 8900 in.3 airgun array. The Sanba 3 profile crosses the southern flank of the Sao Paulo Plateau, the Sao Paulo Ridge and the easternmost Santos Basin in an east–west direction. Its eastern end is located on undisturbed oceanic crust. Tomographic and forward modelling of the wide-angle seismic data reveals that the sedimentary thickness is variable with only 1–2 km on top of the ridge and thickening to 4–5 km in the basin. Crustal thickness at the ridge is about 18 km and the relative layer thickness and velocity gradients indicate a... |
| Tipo: Text |
Palavras-chave: Controlled source seismology; Seismic tomography; Mid-ocean ridge processes; Continental margins: divergent; Continental tectonics: extensional; Crustal structure; South America. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00242/35296/33826.pdf |
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| Klingelhoefer, Frauke; Gutscher, M. -a.; Ladage, S.; Dessa, J. -x.; Graindorge, D.; Franke, D.; Andre, Camille; Permana, H.; Yudistira, T.; Chauhan, A.. |
| The 26 December 2004 Sumatra earthquake (M-w = 9.1) initiated around 30 km depth and ruptured 1300 km of the Indo-Australian-Sunda plate boundary. During the Sumatra-OBS (ocean bottom seismometer) survey, a wide-angle seismic profile was acquired across the epicentral region. A seismic velocity model was obtained from combined travel time tomography and forward modeling. Together with reflection seismic data from the SeaCause II cruise, the deep structure of the source region of the great earthquake is revealed. Four to five kilometers of sediments overlie the oceanic crust at the trench, and the subducting slab can be imaged down to a depth of 35 km. We find a crystalline backstop 120 km from the trench axis, below the fore-arc basin. A high-velocity zone... |
| Tipo: Text |
Palavras-chave: Middle america trench; Fore arc basin; Bottom seismographic observation; Subduction zone; Crustal structure; Accretionary prism; Mantle serpentinization; Aftershock distribution; Megathrust earthquakes; Velocity structure. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00000/11155/7737.pdf |
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| Pinheiro, Joao Marcelo; Schnurle, Philippe; Evain, Mikael; Afilhado, A.; Gallais, Flora; Klingelhoefer, Frauke; Loureiro, Afonso; Fuck, R.; Soares, J.; Cupertino, J. A.; Viana, A.; Rabineau, Marina; Baltzer, Agnes; Benabdellouahed, Massinissa; Dias, N.; Moulin, Maryline; Aslanian, Daniel; Morvan, Laetitia; Maze, Jean-pierre; Pierre, Delphine; Pitel-roudaut, Mathilde; Rio, I; Alves, D.; Barros Junior, P.; Biari, Youssef; Corela, C.; Crozon, Jacques; Duarte, J. L.; Ducatel, Cecile; Falcao, C.; Fernagu, Philippe; Le Piver, David; Mokeddem, Zohra; Pelleau, Pascal; Rigoti, C.; Roest, Walter; Roudaut, Mickael. |
| The structure and nature of the crust underlying the Camamu-Almada-Jequitinhonha-Sergipe-Alagoas basins System, in the NE Brazilian margin, were investigated based on the interpretation of 12 wide-angle seismic profiles acquired during the SALSA (Sergipe ALagoas Seismic Acquisition) experiment in 2014. In this work, we present two 220-km-long NW-SE combined wide-angle and reflection seismic profiles, SL 01 and SL 02, that have been acquired using 15 ocean-bottom-seismometers along each profile, offshore the southern part of the Sergipe Alagoas Basin (SAB), north of the Vaza-Barris Transfer zone. The SL 02 has a 150-km long inland continuation with 20 land-seismic-stations until the Sergipano Fold Belt (SFB). Wide-angle seismic forward modeling allows us to... |
| Tipo: Text |
Palavras-chave: South Atlantic ocean; NE Brazil; Sergipe-Alagoas basin; Passive margins; Wide-angle refraction seismics; Crustal structure; Tectonic inheritance. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57263/59315.pdf |
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| Registros recuperados: 31 | |
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