Geomorphology and sedimentary features in the Central Portuguese submarine canyons, Western Iberian margin

Lastras, Galderic; Arzola, R.G.; Masson, Douglas G.; Wynn, Russell B.; Huvenne, Veerle A.I.; Hühnerbach, Veit; Canals, Miquel

doi:10.1016/j.geomorph.2008.06.013

Cited by 122 publications

(68 citation statements)

References 66 publications

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“…Sedimentology within the Nazaré Canyon, and specifically transport of organo-mineral aggregates (OMAs) of various size classes, has been thoroughly investigated (Schmidt et al, 2001;Thomsen et al, 2002;Van Weering et al, 2002;De Stigter et al, 2007;Oliveira et al, 2007;Arzola et al, 2008;Lastras et al, 2009;Pando et al, 2013). Comparing simulated pellet transport to OMA transport in a comparable model study in the Nazaré Canyon (Pando et al, 2013), indicates that microplastic pellets were modelled to behave more similarly to OMAs of size classes 2 mm and 4 mm than those of 429 µm.…”

Section: Discussionmentioning

confidence: 99%

Modelled transport of benthic marine microplastic pollution in the Nazaré Canyon

et al. 2013

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Abstract. With knowledge of typical hydrodynamic behavior of waste plastic material, models predicting the dispersal of benthic plastics from land sources within the ocean are possible. Here we investigated the hydrodynamic behavior (density, settling velocity and resuspension characteristics) of non-buoyant preproduction plastic pellets in the laboratory. From these results we used the MOHID modelling system to predict what would be the likely transport and deposition pathways of such material in the Nazaré Canyon (Portugal) during the spring/summer months of 2009 and the autumn/winter months of 2011.Model outputs indicated that non-buoyant plastic pellets would likely be transported up and down canyon as a function of tidal forces, with only a minor net down canyon movement resulting from tidal action. The model indicated that transport down canyon was likely greater during the autumn/winter, primarily as a result of occasional mass transport events related to storm activity and internal wave action. Transport rates within the canyon were not predicted to be regular throughout the canyon system, with stretches of the upper canyon acting more as locations of pellet deposition than conduits of pellet transport. Topography and the depths of internal wave action are hypothesized to contribute to this lack of homogeneity in predicted transport.

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Section: Discussionmentioning

confidence: 99%

Modelled transport of benthic marine microplastic pollution in the Nazaré Canyon

et al. 2013

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“…Such features are the main pathways through which shelf sediments are transported, in the form of sediment gravity flows, into the abyssal plains; their geomorphology has been largely ignored, due mainly to their complex terrain and the difficulty in studying the seafloor (Lastras et al, 2009).…”

Section: Seascapes On the Continental Shelfmentioning

confidence: 99%

Morphological characteristics of the Basque continental shelf (Bay of Biscay, northern Spain); their implications for Integrated Coastal Zone Management

et al. 2010

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“…In recent years, high-resolution bathymetric data acquired with latest-generation multibeam and sonar technologies also provides advances in outlining submarine morphological features, and in understanding the sedimentary processes in canyons (Greene et al, 2002;Lastras et al, 2007, Lastras et al, 2009Mountjoy et al, 2009;Paull et al, 2010;Paull et al,2013), and especially at the canyon heads (Smith et al, 2007;Yoshikawa and Nemoto, 2010;Casalbore et al, 2011;Lastras et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Direct sediment transfer from land to deep-sea: Insights into shallow multibeam bathymetry at La Réunion Island

et al. 2013

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Submarine canyon heads are key areas for understanding the triggering factors of gravity currents responsible for the transfer of detrital sediment to the deep basins. This contribution offers a detailed picture of canyon heads off La Réunion Island, with high-resolution multibeam bathymetry in the water depth range of 4-220 m. The present feeding of the Cilaos turbidite system, one of the largest modern volcaniclastic systems in the world, is deduced from morphological and sedimentological interpretations of newly acquired data. The study highlights small-scale sedimentary features indicating hydrodynamic and sedimentary processes.A direct connexion between the Saint-Etienne river mouth and submarine canyons is evidenced by the complete incision of the shelf and the presence of canyon heads connected to the modern deltaic bar. This direct connection, supplied by river torrential floods (cyclonic floods every two or three years), suggests the continuity of high-density fluvial flows to submarine gravity flows, forming hyperpycnal flows in the canyon.The initiation of secondary submarine gravity flows by storm waves (large austral waves and cyclonic waves) is also proposed for submarine canyons with large canyon heads developed in the surf zone from a sandy coastal bar. Bedforms in active canyon axis are considered as an indicator of the frequent activity of high-density turbidity currents.Moreover, a morphological record of last glacial and deglacial sea level variations is preserved, and particularly the Last Glacial Maximum sea level with the presence of small vertical cliffs, observed in this bathymetric data, which likely corresponds to a paleo-shoreline or paleo-reefs.2

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Geomorphology and sedimentary features in the Central Portuguese submarine canyons, Western Iberian margin

Cited by 122 publications

References 66 publications

Modelled transport of benthic marine microplastic pollution in the Nazaré Canyon

Modelled transport of benthic marine microplastic pollution in the Nazaré Canyon

Morphological characteristics of the Basque continental shelf (Bay of Biscay, northern Spain); their implications for Integrated Coastal Zone Management

Direct sediment transfer from land to deep-sea: Insights into shallow multibeam bathymetry at La Réunion Island

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