Jh. Trowbridge, A MECHANISM FOR THE FORMATION AND MAINTENANCE OF SHORE-OBLIQUE SAND RIDGES ON STORM-DOMINATED SHELVES, J GEO RES-O, 100(C8), 1995, pp. 16071-16086
A remarkable set of shore-oblique sand ridges occupies the inner porti
on of the storm-dominated Middle Atlantic and South Atlantic Bights, o
ff the east coast of the United States of America. A mechanism for pre
sent-day formation and growth of these distinctive geological features
follows from a linearized analysis of the stability of alongshore-per
iodic topographical perturbations, based on a depth-averaged fluid dyn
amical model with a simple representation of sediment transport. The a
nalysis indicates exponential growth of shore-oblique features as a re
sult of offshore deflection of storm-driven alongshore flows at ridge
crests, which leads to a convergence of sediment flux because the effe
ctive carrying capacity decreases with increasing distance offshore. T
he analysis indicates a set of conditions required for ridge growth. M
odel solutions for topography under conditions favorable for ridge gro
wth are strikingly similar to the observed sand ridges.