Consulta: subjectFacets:"Sediment drift"
Registros recuperados: 6
Data/hora: 01/06/2024 09:32:19

The impact of internal waves on upper continental slopes: insights from the Mozambican margin (SW Indian Ocean)
Provedor de dados: 5
Autores: Miramontes, Elda; Jouet, Gwenael; Thereau, Estelle; Bruno, Miguel; Penven, Pierrick; Guerin, Charline; Le Roy, Pascal; Droz, Laurence; Jorry, Stephan; Hernández‐molina, F. Javier; Thiéblemont, Antoine; Silva Jacinto, Ricardo; Cattaneo, Antonio.
Evidences of sedimentation affected by oceanic circulation, such as nepheloid layers and contourites are often observed along continental slopes. However, the oceanographic processes controlling sedimentation along continental margins remain poorly understood. Multibeam bathymetry and high‐resolution seismic reflection data revealed a contourite depositional system in the Mozambican upper continental slope composed of a contourite terrace (a surface with a gentle seaward slope dominated by erosion) and a plastered drift (a convex‐shape sedimentary deposit). A continuous alongslope channel and a field of sand dunes (mainly migrating upslope), formed during Holocene, were identified in the contourite terrace at the present seafloor. Seismic reflection data...
Tipo: Text
Palavras-chave: Contourite; Sediment drift; Bedform; Sedimentary processes; Tide; Internal solitary waves; Bottom currents.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00605/71730/70205.pdf

Morphological control of slope instability in contourites: a geotechnical approach
Provedor de dados: 5
Autores: Miramontes, Elda; Garziglia, Sebastien; Sultan, Nabil; Jouet, Gwenael; Cattaneo, Antonio.
Contourite drifts are sediment bodies formed by the action of bottom currents. They are common features found on continental slopes and are often affected by slope failure. However, processes controlling slope instability in contourite depositional systems are still not well constrained, and it is not clear whether contourites have particular properties that make them more susceptible to slope failure. In this study, we compare sedimentological and geotechnical properties of contouritic and hemipelagic sediments within the Corsica Trough (northern Tyrrhenian Sea) using geophysical data sets and sediment cores in order to get a better understanding of the controlling factors of slope stability. Geomorphological and slope stability analyses reveal that...
Tipo: Text
Palavras-chave: Sediment drift; Submarine landslide; Undrained shear strength; Hemipelagite; Mediterranean Sea.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00425/53636/56652.pdf

Contourite identification along Italian margins: The case of the Portofino drift (Ligurian Sea)
Provedor de dados: 5
Autores: Cattaneo, Antonio; Miramontes, Elda; Samalens, Kevin; Garreau, Pierre; Caillaud, Matthieu; Marsset, Bruno; Corradi, Nicola; Migeon, Sebastien.
A brief review of the published evidence of current deposits around Italy is the occasion to test the robustness of matching bottom current velocity models and seafloor morphologies to identify contourite drifts not yet documented. We present the result of the regional hydrodynamic model MARS3D in the Northern Tyrrhenian and Ligurian Sea with horizontal resolution of 1.2 km and 60 levels with focus on bottom current: data are integrated over summer and winter 2013 as representative of low and high intensity current conditions. The Eastern Ligurian margin is impacted by the Levantine Intermediate Water (LIW) with modeled mean velocity of bottom current up to 20 cm s−1 in winter 2013 and calculated bottom shear stress exceeding 0.2 N m−2 in water depth of...
Tipo: Text
Palavras-chave: Sediment drift; Circulation model; Bottom current velocity; Levantine Intermediate Water; Submarine landslide; Mediterranean.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00378/48977/49394.pdf

Size sorting in marine muds: Processes, pitfalls, and prospects for paleoflow-speed proxies
Provedor de dados: 5
Autores: Mccave, I. N.; Hall, I. R.
The basis for, and use of, fine grain size parameters for inference of paleoflow speeds is reviewed here. The basis resides in data on deposited sediment taken in conjunction with flow speed measurements in the field, experimental data on suspended sediment transport and deposition, and theoretical treatments of the generation of size distributions of deposits from suspension controlled by particle settling velocity and flow speed. In the deep sea, sorting events occur under resuspension/deposition events in benthic storms. At flow speeds below 10 - 15 cm s(-1), size in the noncohesive "sortable silt'' ( 10 - 63 mm) range is controlled by selective deposition, whereas above that range, removal of finer material by winnowing also plays a role. The best...
Tipo: Text
Palavras-chave: Sortable silt; Grain size; Paleocurrent; Flow speed; Ocean circulation; Contourite; Sediment drift.
Ano: 2006
URL: https://archimer.ifremer.fr/doc/00234/34515/33417.pdf

The pianosa contourite depositional system (northern Tyrrhenian sea): drift morphology and plio-quaternary stratigraphic evolution
Provedor de dados: 5
Autores: Miramontes Garcia, Elda; Cattaneo, Antonio; Jouet, Gwenael; Thereau, Estelle; Thomas, Yannick; Rovere, Mickael; Cauquil, E.; Trincardi, F.
The Pianosa Contourite Depositional System (CDS) is located in the Corsica Trough (Northern Tyrrhenian Sea), a confined basin dominated by mass transport and contour currents in the eastern flank and by turbidity currents in the western flank. The morphologic and stratigraphic characterisation of the Pianosa CDS is based on multibeam bathymetry, seismic reflection data (multi-channel high resolution mini GI gun, single-channel sparker and CHIRP), sediment cores and ADCP data. The Pianosa CDS is located at shallow to intermediate water depths (170 to 850 m water depth) and is formed under the influence of the Levantine Intermediate Water (LIW). It is 120 km long, has a maximum width of 10 km and is composed of different types of muddy sediment drifts:...
Tipo: Text
Palavras-chave: Sediment drift; Bottom current; Levantine Intermediate Water; Modified Atlantic Water; Mediterranean Sea; Sea level.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00292/40330/38834.pdf

Contourite distribution and bottom currents in the NW Mediterranean Sea: Coupling seafloor geomorphology and hydrodynamic modelling
Provedor de dados: 5
Autores: Miramontes Garcia, Elda; Garreau, Pierre; Caillaud, Matthieu; Jouet, Gwenael; Pellen, Romain; Hernández-molina, F. Javier; Clare, Michael A.; Cattaneo, Antonio.
Contourites are common morphological features along continental margins where currents encounter the seafloor. They can provide long-term archives of palaeoceanography, may be prone to sediment instability, and can have a great potential for hydrocarbon exploration. Despite their importance and increasingly recognised ubiquitous occurrence worldwide, the link between oceanographic processes and contourite features is poorly constrained. In particular, it is unclear under which specific conditions sediments are mobilised, modified and deposited by bottom currents. Here, we aim to determine key bottom current characteristics (velocity and bottom shear stress) affecting contourite deposition, by assuming that recent oceanographic regimes may be extended back...
Tipo: Text
Palavras-chave: Sediment drift; Erosion; Oceanic circulation; Bottom shear stress.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00483/59426/62241.pdf