Journal article
Submarine slide initiation and evolution offshore Pointe Odden, Gabon — Analysis from annual bathymetric data (2004–2009)
Université de Bordeaux, CNRS 5805 EPOC, Avenue des Facultés, 33405 Talence cedex, France1
IOTA SURVEY, 302 rue Charles Lindbergh, CS 90018, 34137 Mauguio Cedex, France2
TOTAL Centre Scientifique et Technique Jean Feger, Avenue Larribau, 64018 Pau Cedex, France3
Service Hydrographique et Océanographique de la Marine (SHOM), 13 rue du Chatellier, 29228 Brest Cedex 2, France4
Time serial bathymetric data acquired between 2004 and 2009 are used to evaluate the morphological evolution of the coastal area offshore Pointe Odden, located on the Mandji Island (Gabon). Data analysis highlights the alternation between fast sedimentation periods at shallow water depth related to intense longshore drift and catastrophic erosional events.
Because of sediment overloading and slope oversteepening, small-scale instabilities are generated (successive slide scars, channel formation and growth by retrogressive erosion). However, when critical stability conditions are reached, large failures occur (2005 submarine slide). Geotechnical measurements and sedimentological analyses on the study area suggest that flow liquefaction would be the triggering mechanism of the 2005 event.
Moreover, our analysis shows that the associated slide scar is rapidly filled by compensation and that failure morphology could disappear from the seafloor in about 15–20years.
| Language: | English |
|---|---|
| Year: | 2012 |
| Pages: | 43-50 |
| ISSN: | 18726151 and 00253227 |
| Types: | Journal article |
| DOI: | 10.1016/j.margeo.2011.11.008 |
