T.M. No. 82 - July 1956 



Changes in Sand Level on the Beach and Shelf at La Jolla, California 

 by D. L. Inman and G. S. Rusnak 



A technique is developed for establishing a reference level on 

 the bottom from which small net changes in sand level can be measured 

 by swimmers equipped with self-contained underwater breathing appa- 

 ratus (SCUBA). Bottom changes were measured periodically for three 

 years at stations from near the surf zone to 70-foot depths. Standard 

 measurement error was about ± 0.05 foot per survey for determination 

 of net sand level. Estimates of sand level variation are made for 

 monthly and seasonal periods and correlated with depth. Comparison 

 with sonic (echo) soundings indicate day-to-day accuracy for the 

 latter method of the order of ± 0.5 foot. 



T.M. No. 85 - June 1956 



Approximate Response of Water Level on a Sloping Shelf to a Wind 

 Fetch Which Moves Towards Shore by R. 0. Re id 



A procedure for evaluating the approximate response character- 

 istics of water level at the shore of a sloping shelf due to a wind 

 fetch moving directly onshore is described. The theory is based 

 upon the linear one-dimensional wave equation and employs the method 

 of characteristics as a means of solution by graphical technique. 

 A total of about 55 separate cases for different values of fetch 

 length and storm speed were investigated numerically, and the 

 primary results summarized in graphical and tabular form. 



T.M. No. 84 - December 1956 



Wave Forecasting Relationships for the Gulf of Mexico 

 by Charles L. Bretschneider 



The methods used in obtaining hindcast statistical wave data for 

 locations in the Gulf of Mexico (presented in Technical Memoranda 

 Nos. 85-89) are discussed. A numerical method of forecasting wave 

 generation and propagation over a sloping bottom taking into account 

 both generation by wind and dissipation by bottom friction is demon- 

 strated. Also shown are the averaging techniques used to apply the 

 method to statistical accumulation of hindcast data in the Gulf 

 of Mexico. 



T.M. No. 85 - September 1956 



Wave Statistics for the Gulf of Mexico off Brown svi I I e, Texas 

 by Charles L. Bretschneider and Roy D. Gaul 



Detailed wave statistics for deep water, 96,/48, 24, and 12-foot 

 depths, based on hindcasts from synoptic weather charts for the 3 

 years, 1950, 1952, 1954, are presented. Refraction coefficients 

 and final wave direction at those depths are presented graphically 

 as a function of wave period and deepwater wave direction. 



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