Open AccessTIME SCALES OF NEARSHORE PROFILE CHANGES
Author(s) -
William A. Birkemeier
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.v19.102
Subject(s) - storm , submarine pipeline , oceanography , bar (unit) , environmental science , climatology , geology , atmospheric sciences
Time scales of nearshore profile change are examined using a unique set of highly accurate surveys collected over a 3% year period at CERC's Field Research Facility. The data are analyzed in terms of the formation and movement of the nearshore bars and with empirical eigenfunctions. The largest and most rapid changes in the profiles occurred during storms. The inner bar (depth of -0.6 to 1.5 m, 1.6 to 4.5 ft) moved offshore during even minor storms and recovered relatively quickly. The outer bar (depth of 3 to 4 m, 9 to 13 ft) formed during the largest storms and recovery was considerably slower, requiring six months or longer. The eigenvector analysis confirmed the importance of storms but identified a seasonal shift of material from the beach and inner bar to the offshore.