Open AccessBEACH FORESHORE RESPONSE TO LONG-PERIOD WAVES
Author(s) -
P.A. Howd,
R.A. Holman
Publication year - 1984
Publication title -
proceedings of conference on coastal engineering/proceedings of ... conference on coastal engineering
Language(s) - English
Resource type - Journals
eISSN - 2156-1028
pISSN - 0589-087X
DOI - 10.9753/icce.v19.132
Subject(s) - intertidal zone , erosion , geology , forcing (mathematics) , sediment , infragravity wave , period (music) , kondratiev wave , deposition (geology) , beach morphodynamics , sediment transport , wave height , climatology , oceanography , geomorphology , wave propagation , physics , longitudinal wave , mechanical wave , quantum mechanics , acoustics , mechanics
A field experiment has been carried out to test the hypothesis that infragravity and lower frequency waves influence patterns of erosion and deposition on the beach foreshore. The data show coherent fluctuations in the foreshore sediment level which can be related to low frequency wave motions. The fluctuations have heights of up to 6 cm with typical time scales of 8 to 10 minute periods. They can be characterized in two ways: by the progression of the fluctuation up the foreshore slope (landward), and by the decrease in the root-mean-square (RMS) height of the fluctuations as they progress landward. Analysis of runup time series obtained by time-lapse photography concurrent with the sediment level measurements reveals long-period waves of undetermined origin which are positively correlated with the sediment level fluctuations. This strongly suggests that the waves are responsible for forcing the sediment level fluctuations.