PROGRESS REPORTS Oti RESEARCH SPONSORED BY 

 THE BEACH EROSION BOARD 



Summaries of progress made during fiscal year 1939 on the 

 several research contracts in force between universities or other 

 institutions and the Beach Erosion Board, together with brief 

 statements as to the status of some research projects being prose- 

 cuted in the laboratory of the Beach Erosion Board, are presented 

 below. These summaries supplement and continue those contained in 

 prior issues of the Bulletin. 



I. University of California, Contract DA-49-055-eng-8, Sources of 

 Beach Sand . 



Seasonal sampling of Point Reyes Beach and other beaches in the 

 San Francisco area was continued. In addition to Point Reyes Beach, 

 two other beaches north of San Francisco Harbor entrance (the beach 

 at Drakes Bay and St ins on Beach opposite Bolinas Bay) are being 

 studied. Four beaches south of San Francisco Harbor are being occupied. 

 These are the beaches of Golden Gate Park, Fleischacker Zoo, Sharps 

 ?oint, and Rockaway Beach. These beaches have been occupied at 2 to 6- 

 week periods during the last two years, and a report "Beaches Near 

 San Francisco, California 1956-1957" has been published as Technical 

 Memorandum No. 110 of the Board describing these observations. A 

 further report entitled "Mechanical Analysis of Beach Sands Near San 

 Francisco, California" tabulating the basic data for the previous paper 

 has been prepared for limited distribution as University of California 

 Institute of Engineering Research Report, Series 14, Issue 22. Mineral 

 analyses of some of the samples are now being made in order to obtain 

 further indications of the direction of migration of the sand; measure- 

 ments of the radioactivity of the sand are also planned in the hope 

 that variations in the ccsitent of mazonite (a thorium-bearing mineral) 

 may also indicate the drift direction. 



II. Massachusetts Institute of Technology, Contract DA-49-055-eng-16 . 

 Sorting of Beach Sand by Waves . 



A report entitled "The Damping of Oscillatory Waves by Laminar 

 Boundary Layers" is being published as Technical Memoreindum No. 117 

 of the Board. It discusses the measurements of bottom shearing stress 

 exerted by shallow water waves obtained in a small wave flume. Methods 

 of predicting resistance coefficients are derived. All of the tests 

 indicated a laminar boundtiry layer, and consequently coefficients are 

 applicable to laminar flow only. Several tests were also made to 

 compare experimentally determined equilibrium profiles with those 

 predicted by the theory previously derived in this study (see Beach 

 Erosion Board Technical Memorandum No. 104). The theoretical 



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