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Titel |
Mapping turbidity layers using seismic oceanography methods |
VerfasserIn |
E. A. Vsemirnova, R. W. Hobbs, P. Hosegood |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1812-0784
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Digitales Dokument |
URL |
Erschienen |
In: Ocean Science ; 8, no. 1 ; Nr. 8, no. 1 (2012-01-10), S.11-18 |
Datensatznummer |
250005393
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Publikation (Nr.) |
copernicus.org/os-8-11-2012.pdf |
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Zusammenfassung |
Using a combination of seismic oceanographic and physical oceanographic data
acquired across the Faroe-Shetland Channel we present evidence of a
turbidity layer that transports suspended sediment along the western
boundary of the Channel. We focus on reflections observed on seismic data
close to the sea-bed on the Faroese side of the Channel below 900 m. Forward
modelling based on independent physical oceanographic data show that
thermohaline structure does not explain these near sea-bed reflections but
they are consistent with optical backscatter data, dry matter concentrations
from water samples and from seabed sediment traps. Hence we conclude that an
impedance contrast in water column caused by turbidity layers is strong
enough to be seen in seismic sections and this provides a new way to
visualise this type of current and its lateral structure. By inverting the
seismic data we estimate a sediment concentration in the turbidity layers,
present at the time of the survey, of 45 ± 25 mg l−1. We believe this is the
first direct observation of a turbidity current using Seismic Oceanography. |
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