Titre :

Geomorphic evolution of a coastal mudflat under oceanic influences: an example from the dynamic shoreline of French Guiana

Auteur(s) :

Lefebvre, Jean Pierre [Auteur]
École normale supérieure - Paris [ENS-PSL]
Dolique, Franck [Auteur]
Université du Littoral Côte d'Opale [ULCO]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Laboratoire de géomorphologie dynamique et aménagement des littoraux [GéoDAL]
Gratiot, Nicolas [Auteur]
Laboratoire d'étude des transferts en hydrologie et environnement [LTHE]

Titre de la revue :

Marine Geology

Pagination :

191-205

Éditeur :

Elsevier

Date de publication :

2004-08-15

ISSN :

0025-3227

Mot(s)-clé(s) en anglais :

estuarine mudcape
mudbank
littoral fringe
fluid mud layer

Discipline(s) HAL :

Planète et Univers [physics]
Planète et Univers [physics]/Interfaces continentales, environnement
Planète et Univers [physics]/Océan, Atmosphère
Planète et Univers [physics]/Sciences de la Terre
Planète et Univers [physics]/Sciences de la Terre/Géomorphologie
Planète et Univers [physics]/Sciences de la Terre/Océanographie

Résumé en anglais : [en]

The dynamics of the shoreline in French Guiana are characterized mainly by the northwestward migration of nearshoremudbanks. The passage of these features is responsible for significant geomorphic changes at the shoreline, ...
Lire la suite >The dynamics of the shoreline in French Guiana are characterized mainly by the northwestward migration of nearshoremudbanks. The passage of these features is responsible for significant geomorphic changes at the shoreline, such as the creationand erosion of extensive mudflats and the deviation of estuarine river mouths. Indeed, the hydrodynamic perturbation of themean alongshore coastal currents generated by river discharge and tidal outflow from these estuaries can result in theimmobilization of parts of a migrating mudbank, leading to the creation of a mudflat. Due to the general northwestwarddirection of coastal oceanic dynamics in this area, such mudflat development always occurs southeast (updrift) of the rivermouths and consequently contributes to their northwestward diversion, forming a mudcape. Erosional processes on the marineside of mudcapes often result in a secondary outlet channel that gradually replaces the former main channel.In order to quantify the rate of these geomorphic changes, monitoring of an estuarine area was carried out at different timescales: on a decadal basis, from 1951 to 2001, with airborne sensing data, and over a shorter period covering a completeinterbank situation (i.e., between the passage of two successive mudbanks), from 1999 to 2002, by means of field surveys andairborne digital videography. This short-term morphological monitoring was conducted from the early stage of mudflatconsolidation and mangrove colonization to the arrival of the following mudbank at the edge of the study area. Various modesof erosion and the diversity of the eroded topography were highlighted by the study. Other aspects brought out by the work arethe rate of mangrove colonization and its influence on the erosion processes, the influence of the tide on geomorphic processes,and the role of pioneer fluid mud deposits, related to the proximity of the next mudbank, on the dynamics of the mudflat system.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Collections :

• Laboratoire d'Océanologie et de Géosciences (LOG) - UMR 8187

Source :

Harvested from HAL