Morpho-sedimentary and -dynamic characteristics of the Bay of Somme Michel C.a, Le Bot S.a, Druine F.a, Costa S.ac, Levoy F. b, Brunaud C.b and Lafite R.a
[email protected] a : Normandie Univ, UNIROUEN, UNICAEN, CNRS, M2C, 76000 Rouen, France b : Normandie Univ, UNICAEN, UNIROUEN, CNRS, M2C, 14000 Caen, France c : Normandie Univ, UNICAEN, CNRS, LETG, 14000 Caen, France 1°0'W 0°0' 1°0'E 2°0'E 1°30'E 1°35'E 1°40'E 1°30'E 1°35'E 1°40'E N N SEDIMENT MAP N DYNAMIC MAP Rue Rue N N Sedimentological Dynamic zonation on the ' ' 6 6 zonation in 2013: 2011-2013 period: 1 Bay of 1 Pointe de Pointe de ° ° 0 Somme 0 St-Quentin S1 Muddy sand and sandy mud, St-Quentin D1 Stability 5 5 poorly sorted, with a strong D2 Eastern English Channel La Maye La Maye Picardy CaCO3 content D2 Strong dynamics due to migration of bedforms S2 Sand, moderately sorted to well sorted, with a low CaCO3 content D3 Strong dynamics due to D1 channel migration S3 Sand and slightly gravelly sand, Le Marais moderately sorted, with a very Le Marais 10 10 low CaCO3 content 10 N N D2 D2 ' ' Dynamic zonation N ' 4 4 CaCO3 content in 2013 (%) 0 1 1 S2 Lowest Astronomical Tide ° ° Bay of ° 0 0 0 Sedimentological zonation 5 5 Seine 5 Lowest Astronomical Tide Altimetric variation on the 10 40 20 30 02/06/2012-01/04/2013 Le Crotoy D2 Le Crotoy Mean grain size in 2013 D2 period (m) S3 (µm) 4.17 1.5 ± Le Hourdel 62 - 100 Le Hourdel English Channel 100 - 150 D3 Normandy 1.0 N N 1 150 - 200 ' ' S 2 2 1 1 200 - 250 ° ° 0.5 0 0 D1 5 5 La Mollière 250 - 300 La Mollière 10 10 300 - 350