Seismic and oceanographic evidence of present-day bottom-water dynamics in the Lousy Bank-Hatton Bank area, NE Atlantic

L. Due, H.M. van Aken, L.O. Boldreel, A. Kuijpers

Publikation: Bidrag til tidsskriftArtikelForskningpeer review

9 Citationer (Scopus)

Abstrakt

High-resolution multi-channel seismic records from the eastern margin of the Iceland Basin, Northeast Atlantic, are used to infer regional patterns of bottom water dynamics from seafloor morphology and distribution of the most recent geological units deposited along the margin. This information is combined with results from oceanographic and hydrodynamic measurements made in the area. The study area is located between Lousy Bank and Hatton Bank, where deep-water currents are forced around structural highs, leaving a complex pattern of topographically controlled sediment transport pathways. At the top and upper flank of Lousy Bank, George Bligh Bank and Hatton Bank topographic forcing leads to considerable acceleration of the northward flowing North Atlantic Current. At greater water depth, seismic facies indicative of bottom current action are found to be widespread. In addition, seafloor morphology displays moat features extending over large distances. The occurrence of these moats is confined to specific water depths in the range from 700-1400 m and from 1800 to 2200 m depth range. These depth ranges correspond to the basal depth stratum of the North Atlantic Current and the depth range of the Deep Northern Boundary Current, respectively. Geological evidence suggests maximum near-bottom current speed of about 0.5 m/s for these moat areas. Using oceanographic data we suggest that formation of the moats is not likely to be associated with the presence of a persistent high-speed contour current core, but probably originates from the occurrence of solibores and thus may be related to the internal wave field of the Iceland Basin possible linked to atmospheric pressure variation.

OriginalsprogEngelsk
Sider (fra-til)1729-1741
Antal sider13
TidsskriftDeep-Sea Research Part I: Oceanographic Research Papers
Vol/bind53
Udgave nummer11
DOI
StatusUdgivet - nov. 2006

Programområde

  • Programområde 5: Natur og klima

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