The Saint-Gcorges Bank is associated to the proximal Pointe de Suzac
headland. Then, according to the recent Dyer & Huntlev’s classification
(1999), the bank can be either of type 3A: “banner banks” created by the
tidal eddies produced by the headlands, or of type 2A : “estuarine wide
mouth sandbank” tide-dominated bank with a mutually evasive net
bedload transport characterising an area of high shear tress between the
ebb and flood dominated channels of sand transport. In both cases, it is
suggested that secondary flows may be relevant to the maintenance of
the sandbank. However these flows are likely to be smaller than the
primaty tidal flows. It appears that a more accurate understanding of
the interaction between tidal flows and secondary circulations over the
Saint-Georges Bank is required. For this reason, although the analysis of
the Swamgir-2 measurements are still in progress, extensive field work
has been organised in May 2000 around the Saint-Georges Bank comprising continuous ADCP transects survey and the deployment of several
current meters.
Acknowledgments
This work is funded by the SWAMIEE Project of the TMR ituropean (iommission. The
authors would likc to thank all the technical staff who assisted in the instrument preparation and in particular J. Davis (University of Southampton), P. Ganderton (Oniversity of Plymouth), A. de Resseguier (Université de Bordeaux 1), G. Oggian (Université
de Bordeaux 1) and F. Pinet (Observatoire du littoral de Rovan).
Bibliographic references
Dyer K.R., Huntley D.A., 1999. The origin, classification and modelling
of sand banks and ridges. Cont. Shelf Res., 19,1285-1330.
1 lulscher S.J, De Swart H.T, De Vriend H.J., 1993. The generation of offshore tidal sand banks and sand waves. Cont. Shelf Res., 13, 11831204.
Mallet C, Howa 11., Garlan, T, Sottoiichio A., I e 1 lir P., 2000. Rcsidual
transport model in correlation with sedimentarv dvnamics over an
elongated tidal sandbar in the Gironde estuary (SW France). J. Sediment. Res., 70(5), 100.3 1016.
Pattiaratchi (.., Collins M.B., 1987. Mechanisms for linear sandbanks
formation and maintenance in relation to dvnamical oceanographic
obsen ations. Process ( Oceanogr., 19, 117-176.
Pingree, R.D., 1978. The formation of the shambles and other banks by
tidal stirring of the seas. |. Mar. Biol. Assoc., 58, 211-226.
Port autonome de Bordeaux, 1980. Ftude sédimentologique des plages
de Saintonge et du banc de Saint-Georges. Rapp. Intern., 30 p.
228
headland. Then, according to the recent Dyer & Huntlev’s classification
(1999), the bank can be either of type 3A: “banner banks” created by the
tidal eddies produced by the headlands, or of type 2A : “estuarine wide
mouth sandbank” tide-dominated bank with a mutually evasive net
bedload transport characterising an area of high shear tress between the
ebb and flood dominated channels of sand transport. In both cases, it is
suggested that secondary flows may be relevant to the maintenance of
the sandbank. However these flows are likely to be smaller than the
primaty tidal flows. It appears that a more accurate understanding of
the interaction between tidal flows and secondary circulations over the
Saint-Georges Bank is required. For this reason, although the analysis of
the Swamgir-2 measurements are still in progress, extensive field work
has been organised in May 2000 around the Saint-Georges Bank comprising continuous ADCP transects survey and the deployment of several
current meters.
Acknowledgments
This work is funded by the SWAMIEE Project of the TMR ituropean (iommission. The
authors would likc to thank all the technical staff who assisted in the instrument preparation and in particular J. Davis (University of Southampton), P. Ganderton (Oniversity of Plymouth), A. de Resseguier (Université de Bordeaux 1), G. Oggian (Université
de Bordeaux 1) and F. Pinet (Observatoire du littoral de Rovan).
Bibliographic references
Dyer K.R., Huntley D.A., 1999. The origin, classification and modelling
of sand banks and ridges. Cont. Shelf Res., 19,1285-1330.
1 lulscher S.J, De Swart H.T, De Vriend H.J., 1993. The generation of offshore tidal sand banks and sand waves. Cont. Shelf Res., 13, 11831204.
Mallet C, Howa 11., Garlan, T, Sottoiichio A., I e 1 lir P., 2000. Rcsidual
transport model in correlation with sedimentarv dvnamics over an
elongated tidal sandbar in the Gironde estuary (SW France). J. Sediment. Res., 70(5), 100.3 1016.
Pattiaratchi (.., Collins M.B., 1987. Mechanisms for linear sandbanks
formation and maintenance in relation to dvnamical oceanographic
obsen ations. Process ( Oceanogr., 19, 117-176.
Pingree, R.D., 1978. The formation of the shambles and other banks by
tidal stirring of the seas. |. Mar. Biol. Assoc., 58, 211-226.
Port autonome de Bordeaux, 1980. Ftude sédimentologique des plages
de Saintonge et du banc de Saint-Georges. Rapp. Intern., 30 p.
228