Physical Linkages Between Offshore Bathymetry and Surf Zone Morphologic Change

TitlePhysical Linkages Between Offshore Bathymetry and Surf Zone Morphologic Change
Publication TypeJournal Article
Year2017
AuthorsHansen, J, Raubenheimer, B, Elgar, S, List, J, Lippmann, TC
JournalJournal of Geophysical Research
Volume122(4)
Pages3451-3460
Date PublishedMarch 23
PublisherAGU

The causes of surf zone morphologic changes observed along a sandy beach onshore of a submarine canyon were investigated using field observations and a numerical model (Delft3D/SWAN). Numerically simulated morphologic changes using four different sediment transport formulae reproduce the temporal and spatial patterns of net cross‐shore integrated (between 0 and 6.5 m water depths) accretion and erosion observed in a ∼300 m alongshore region, a few hundred meters from the canyon head. The observations and simulations indicate that the accretion or erosion results from converging or diverging alongshore currents driven primarily by breaking waves and alongshore pressure gradients. The location of convergence or divergence depends on the direction of the offshore waves that refract over the canyon, suggesting that bathymetric features on the inner shelf can have first‐order effects on short‐term nearshore morphologic change.

DOI10.1002/2016JC012319
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