Geo-Marine Letters

, 27:391

Do bottom-intensified diurnal tidal currents shape the alignment of carbonate mounds in the NE Atlantic?

  • Martin White
  • J. Murray Roberts
  • Tjeerd van Weering
Original

DOI: 10.1007/s00367-007-0060-8

Cite this article as:
White, M., Roberts, J.M. & van Weering, T. Geo-Mar Lett (2007) 27: 391. doi:10.1007/s00367-007-0060-8

Abstract

Measurements of near-seabed currents at different carbonate mound locations have demonstrated the presence and influence of bottom-magnified diurnal-period tidal motions. These bottom-trapped waves occur at a depth where the product of local vertical density stratification and seabed slope is a maximum. The seabed currents are magnified significantly if the diurnal forcing period is resonant with the combination of stratification and seabed slope. At the Belgica mounds (eastern Porcupine Sea Bight), there is a correlation between the cross-slope alignment of individual carbonate mounds and the direction of the major axis of the largest (diurnal) tides. The pattern suggests that the enhanced tidal currents play a major role in the shape of developing mounds over a long time period. A similar relation appears to hold at the Logachev mounds (SE Rockall Bank), although less clear because tides are not amplified to the same degree. At other mound locations where enhanced diurnal currents are not present, a more irregular distribution is observed. This suggests that the diurnal currents may be important only at certain carbonate mound locations, and that at these locations a more distinctive alignment of mound structures is produced.

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Martin White
    • 1
  • J. Murray Roberts
    • 2
  • Tjeerd van Weering
    • 3
  1. 1.Department of Earth and Ocean SciencesNational University of IrelandGalwayIreland
  2. 2.Dunstaffnage Marine LaboratoryScottish Association for Marine ScienceArgyllUK
  3. 3.Royal Netherlands Institute for Sea Research (NIOZ)TexelThe Netherlands