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Titel |
Effects of storm events on the shelf-to-basin sediment transport in the southwestern end of the Gulf of Lions (Northwestern Mediterranean) |
VerfasserIn |
A. Palanques, P. Puig, J. Guillén, X. Durrieu de Madron, M. Latasa, R. Scharek, J. Martin |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Science ; 11, no. 3 ; Nr. 11, no. 3 (2011-03-15), S.843-850 |
Datensatznummer |
250009265
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Publikation (Nr.) |
copernicus.org/nhess-11-843-2011.pdf |
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Zusammenfassung |
Shelf-to-basin sediment transport during storms was studied at the
southwestern end of the Gulf of Lions from November 2003 to March 2004.
Waves, near-bottom currents, temperature and sediment fluxes were measured on
the inner shelf at 28-m depth, in the Cap de Creus submarine canyon head at
300-m depth and in the northwestern Mediterranean basin at 2350-m depth. This
paper is a synthesis of results published separately in different papers; it
includes some new data and focusses on the subject of storms. It is the first
paper in which simultaneous data about the effect of storms on the shelf, the
slope and in the basin are shown together. During the winter studied, there
were two severe E-SE storms with significant wave heights ≥ 7 m: one in
December 2003 and one in February 2004. During these storms, coastal water
was exported off-shelf producing strong near-bottom currents (up to
82 cm s−1) at the canyon head that resuspended sediment and increased
the downcanyon sediment fluxes by several orders of magnitude. The suspended
sediment flux increase in the canyon head was much larger during the February
storm than during the December storm. At the deep basin site, particle fluxes
also increased drastically (1–2 orders of magnitude) immediately after the
February storm but not after the December storm. The reason was that the
February storm was reinforced by dense shelf water cascading and was long
enough (43 h) to transfer large amounts of resuspended sediment from shallow
shelf areas to the canyon head and from there to the northwestern
Mediterranean basin. Thus, in the western Gulf of Lions, severe winter E-SE
storms occurring during the dense shelf water cascading period can
significantly increase the transfer to deep-sea (> 2000 m) environments of
shelf and slope resuspended material, including anthropogenic contaminants
and organic matter. |
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