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	Provedor de dados ArchiMer (3) Autor Arnulf, A. F. (1) Charvis, P (1) Crawford, W. C. (1) Geli, Louis (1) Goslin, J (1) Harding, A. J. (1) Kent, G. M. (1) Klingelhofer, Frauke (1) Matias, Luis (1) Mohr, J (1) Operto, S (1) Recq, M (1) Singh, Shubpreet (1) Steinsland, N (1) Mais... Palavra-chave Seismic refraction (3) Oceanic crust (2) Aseismic ridge (1) Crozet Islands platform (1) Crustal structure (1) Downward continuation (1) Gravity anomalies (1) Hotspots (1) Lucky Strike (1) Mantle (1) Mid-Atlantic Ridge (1) Mohns Ridge (1) Tomography (1) Mais... Tipo do documento Text (3) Ano 2014 (1) 2000 (1) 1998 (1) País France (3) Idioma Inglês (3)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 3 Primeira ... 1 ... Última Constraints on the shallow velocity structure of the Lucky Strike Volcano, Mid-Atlantic Ridge, from downward continued multichannel streamer data ArchiMer Arnulf, A. F.; Harding, A. J.; Kent, G. M.; Singh, Shubpreet; Crawford, W. C.. The shallow velocity structure of the Lucky Strike segment of the Mid-Atlantic Ridge is investigated using seismic refraction and reflection techniques applied to downward continued multichannel streamer data. We present a three-dimensional velocity model beneath the Lucky Strike Volcano with unprecedented spatial resolutions of a few hundred meters. These new constraints reveal large lateral variations in P wave velocity structure beneath this feature. Throughout the study area, uppermost crustal velocities are significantly lower than those inferred from lower resolution ocean bottom seismometer studies, with the lowest values (1.8–2.2 km/s) found beneath the three central volcanic cones. Within the central volcano, distinct shallow units are mapped that... Tipo: Text Palavras-chave: Mid-Atlantic Ridge; Lucky Strike; Seismic refraction; Tomography; Oceanic crust; Downward continuation. Ano: 2014 URL: http://archimer.ifremer.fr/doc/00185/29598/27965.pdf Small-scale crustal variability within an intraplate structure: the Crozet Bank (southern Indian Ocean) ArchiMer Recq, M; Goslin, J; Charvis, P; Operto, S. The Crozet Bank, the easternmost region of the Crozet Plateau (austral Indian Ocean), is capped by two groups of islands which form the Crozet Archipelago (Terres Australes and Antarctiques Francaises). A N-S-trending 2 km deep basin, the Indivat Basin, extends between the two groups of islands and bisects the Crozet Bank into two separate domains. The interpretation of the KeOBS8 seismic refraction profile shot during the KeOBS/MD66 cruise (January-February 1991) over the eastern Crozet Plateau was carried out by ray tracing and the computation of synthetic seismograms. This interpretation leads to a rather complex seismic structure and outlines a pronounced eastward crustal thinning from 16.5 to 10 km at the expense of layer 2. The thinning of the crust... Tipo: Text Palavras-chave: Aseismic ridge; Crozet Islands platform; Crustal structure; Gravity anomalies; Hotspots; Seismic refraction. Ano: 1998 URL: https://archimer.ifremer.fr/doc/00297/40789/39805.pdf Crustal structure of a super-slow spreading centre: a seismic refraction study of Mohns Ridge, 72 degrees N ArchiMer Klingelhofer, Frauke; Geli, Louis; Matias, Luis; Steinsland, N; Mohr, J. A series of eight high-resolution seismic refraction profiles from the ultra-slow spreading (16 mm yr(-1) full spreading rate) Mohns Ridge in the Norwegian-Greenland Sea has been treated with modern inversion methods. The profiles were shot parallel to the ridge at an off-axis distance of 0-135 km corresponding to crustal ages of 0-22 Ma. The resulting models are constrained by synthetic seismograms and gravity modelling.The crustal thickness in all profiles is well below the global average for typical oceanic crust, and shows a high variability with a mean thickness of 4.0 +/- 0.5 km. This is mainly due to a very thin and variable lower crustal layer (Layer 3). Generally, the crust is thicker beneath basement highs and thinner beneath basins, implying... Tipo: Text Palavras-chave: Seismic refraction; Oceanic crust; Mohns Ridge; Mantle. Ano: 2000 URL: https://archimer.ifremer.fr/doc/2000/publication-681.pdf Registros recuperados: 3 Primeira ... 1 ... Última

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