19 June 2001
BEACH CUSP FORMATION AND SPACINGS AT DUCK, NC
K. T. Holland
Naval Research Laboratory
Stennis Space Center, MS 39529-5004
Abstract
This investigation involved the analysis of nearly nine years of video imagery from Duck, NC to determine the timing of cusp formation (to within half a day) and the distances separating consecutive cusp horns (to within half a meter). Supplementary data provided by nearshore instrumentation and surveying vehicles was used to document the environmental conditions during cusp development. These extensive observations conclusively demonstrate that cusps at this location develop following storms during the transition from high energy to low energy wave conditions as the wave angle approaches normal incidence. The average cusp width over the 57 independent cusp events was approximately 25 m. The mean variation within an individual cusp system from the average cusp spacing was about 15%. A peculiar suggestion of historisis within the cusp spacing time series was observed and may suggest that existing theories of cusp formation need to be reformulated.
Sponsored by the Office of Naval Research.
Published in
the Journal of Continental Shelf Research, Vol. 18 (10), August 1998. Naval
Research Laboratory Contribution Number NRL/JA/7442 96-0018.
Journal Article