SUSPENDED-SEDIMENT TRANSPORT IN THE SURF ZONE - RESPONSE TO BREAKING WAVES

A field experiment designed to investigate the influence of wave break ing on suspended-sediment transport was conducted at Duck, NC, from 6 to 9 September 1985. Arrays of optical backscatter sensors, electromag netic current meters and pressure sensors were deployed at five positi ons on a shore-normal transect that spanned the surf zone. At each pos ition measurements were made of cross-shore and longshore velocity, se a-surface fluctuations, and suspended sediment at five levels above th e bed. Experimental data runs were conducted when incident swell waves (H-s = 0.5 m, T = 10-12 s) broke (primarily plunging) within the expe rimental transect. This paper describes the spatial characteristics of the plunge-to-bore tranformation region and describes (1) the cross-s hore variability of sediment resuspension, including the mean concentr ations and mean suspended load; (2) the net longshore and cross-shore flux across the surf zone; (3) mean suspended-sediment profiles as a f unction of wave type, e.g. plunging, spilling and bore, and unbroken a t four positions across the surf zone; and (4) discusses the relative contribution of each wave type to the net longshore and cross-shore se diment flux. Copyright (C) 1996 Elsevier Science Ltd