Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/3395
Title: Wave-generated ripples in nearshore sands
Authors: Scripps Institution of Oceanography
United States. Army. Office of the Chief of Engineers
Inman, Douglas L. (Douglas Lamar), 1920-2016
Keywords: Sand waves
Sand ripples
Ripple-marks
Water waves
Publisher: United States, Beach Erosion Board
Engineer Research and Development Center (U.S.)
Series/Report no.: Technical memorandum (United States. Beach Erosion Board) ; no. 100.
Description: Technical Memorandum
Abstract: A study of the formation and occurance of sand ripples generated by oscillatory wave motion was made in coastal waters to gain a better understanding of the role ripples play in the sorting and transportation of sediments. The observations, which extend from the surf zone to depths of about 170 feet, were made by swimmers equipped with self-contained underwater breathing apparatus. The wave length, crest length, height and symmetry of the ripples were measured and these parameters compared with the size of the sand and with the orbital displacement and velocity of the wave motion generating the ripples. Ripples were always present on sandy bottoms when the significant orbital velocity had a value between 1/3 and 3 feet per second. The type of ripple was related to the size of the sand and the nature and rigor of the wave motion. The ripple wave length ranged from 0.14 feet in fine sand to over 4 feet in very coarse sands. The heights of the ripples ranged from about one-fourth to one-sixteenth of the ripple wave length. In areas of abundant sand, the largest and least dense material occured on the ripple crests and the finest and heaviest in the trough. Over rocky bottoms where there was little sand, the relationship was frequently reversed. The ripple crest consisted of sand washed from among the rocks while the coarse material remained in the trough.
Rights: Approved for Public Release, Distribution is Unlimited
URI: http://hdl.handle.net/11681/3395
Appears in Collections:Technical Memorandum

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