Beach cusp characteristics and the hydrodynamic conditions of formation inmacrotidal environments

Citation
O. Monfort et al., Beach cusp characteristics and the hydrodynamic conditions of formation inmacrotidal environments, B SOC GEOL, 171(6), 2000, pp. 649-656
Citations number
41
Categorie Soggetti
Earth Sciences
Journal title
BULLETIN DE LA SOCIETE GEOLOGIQUE DE FRANCE
ISSN journal
00379409 → ACNP
Volume
171
Issue
6
Year of publication
2000
Pages
649 - 656
Database
ISI
SICI code
0037-9409(2000)171:6<649:BCCATH>2.0.ZU;2-V
Abstract
Beach cusps are sometimes present on the upper foreshore of sandy beaches a long the northwest coast of France characterised by very large tidal ranges . These forms were observed on the high tidal zone of Luc-sur-Mer in the "b aie de Seine" during morphodynamic surveys conducted between May and July 1 996. Topographic surveys showed these cusps to be depositional features. Th e profile and incident wave characteristics do not favour the theory of cus p formation based on the presence of subharmonic edge waves, while the spac ing between the horns is in disagreement with the theory of "self-organisat ion''. The wave record on the lower beach shows, at the time of their appea rance, two incident wave trains each with a specific direction and period. The observed beach cusps appear to be induced by the intersection of these two wave trains, thus confirming, for the first time in the field observati ons, experiments conducted in laboratory.