studied surface features of coral reefs are briefly 

 summarized and application of these basic data to 

 the interpretation of aerial photographs of coral 

 reefs is discussed. 44 photographs depicting variable 

 and common surface features of coral reefs are in- 

 cluded and discussed. 



NO. 5 - May 1944 



I-D "A Wave Method for Determining Depths Over Bottom Dis- 

 continuities" by Dr. Martin A. Mason and Dr. 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, but field check of the experimental results 

 was not possible at the time. 



NO. 6 - October 1948 



II-A "An Ocean Wave Measuring Instrument" by Joseph M. Caldwell 

 D 



Methods for measuring height and period of water waves 

 and their relative advantages and disadvantages are 

 discussed. The development of a step-resistance staff 

 gage for measuring fluctuations of the sea surface at 

 the gage site is described in detail and is concluded 

 to be a satisfactory and accurate instrument. The gage 

 is not suitable for use in locations where a suitable 

 supporting structure is not available. 



NO. 7 - September 1944 



I-C "Shore Currents and Sand Movement on a Model Beach" by 

 W. C. Krufflbein 



Uniform waves were run at an angle to a sloping sand 

 beach in a laboratory wave tank, and the alongshore 

 current and sand movement measured. Relation of along- 

 shore current velocity, rate of sand movement, and wave 

 characteristics were studied on a small scale basis, 

 but utilizing dimensionless parameters. Relations of 

 beach slope and sand sorting to wave characteristics 

 were also studied. 



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