Section 2. TECHNICAL MEMORANDA OF THE BEACH EROSION BOARD 



T.M. No. I - May 1940 



A Model Study of the Effect of Submerged Breakwaters on Wave Action 

 by Wil I iam C. Ha I I 



A model study to determine the effect, under varied conditions, 

 of underwater sills upon wave heights and power. General conclusions 

 regarding shape and effectiveness of such structures are presented. 



T.M. No. 2 - February 1942 



Abrasion of Beach Sand by Martin A. Mason 



A study to examine the rate of loss by abrasion to ascertain 

 its importance in beach erosion processes. The work by others is 

 examined. Experiments at the Laboratory submitting anthracite coal 

 to wave action in a laboratory wave tank are discussed. Loss of beach 

 material caused by abrasion is of very minor importance compared to 

 losses and gains caused by littoral movement. 



T.M. No. 5 - May 1944 



Shore Processes and Beach Characteristics by W. C. Krumbein 



A study of the interrelationships between natural variables 

 involved in beach phenomena. Relations between wave energy, beach 

 slopes, sand size, erosion and deposition are studied and discussed 

 for the compartmented coastal region of Half Moon Bay, California 

 with its associated headlands, beaches, and cliffs. 



T.M. No. 4 - May 1944 



Surface Features of Coral Reefs by Lincoln Dryden 



Brief summary of data obtained by investigators who have 

 measured and studied surface features of coral reefs. Application of 

 of these basic data is related to the interpretation of aerial photo- 

 graphs of coral reefs. Photographs depicting variable and common 

 surface features of coral reefs are included and discussed. 



T.M. No. 5 - May 1944 



A Wave Method for Determining Depths Over Bottom Discontinuities 

 by Martin A. Mason and Garbis H. Keulegan 



A method is presented for determining water depth over bottom 

 discontinuities by measuring comparative wave lengths from aerial 

 photographs. The formula of comparison was determined experimentally 

 in a model wave tank for reefs of three different physical conditions. 

 Field check of the experimental results was not possible at this time. 



