TIL. Seripps Institution of Oceanography, Quarterly Progress Heport 
No. 16, Contract No. W-4)9-055-eng-3, April-June 1953. 
pe a a i Se eS Se 
The field phase of the investigation of orbital velocities has been 
completed. Preliminary investigation of wave data indicates that the relation 
between mean water depth d, depth under the wave trough h, and the wave 
height H can be expressed empirically as d-h = kH, where k is a constant for 
a given series of observations. To date k has been found to range from about 
0.1 to 0.2, which means that for a given height, measured from wave trough 
to wave crest, approximately 80 to 90 percent is above mean water level. 
The program of underwater observations by swimmers equipped with self- 
contained diving gear is being expanded. At present, objectives are (Gi) 
studies of the mechanics of sand transport, (2) accurate measurements of 
cut and fill by means of reference rods, and (3) development and improvement 
of equipment and techniques for underwater studies. Cut and fill of the 
sandy bottom in water depths of 52 and 70 feet based on averages of six rods 
at each station, has been negligible (+ 0.02 feet). Measurements in shoaler 
areas indicate somewhat greater changes. 
Comparison has been made between the amount of shoaling and deepening 
of the valley axes at the head of Scripps Submarine Canyon between surveys. 
The surprising result is that there are indications that shoaling takes 
place at a relatively rapid rate following deepening. Afber a submarine 
landslide, rapid fill takes place at the very head of the valley and then 
progresses gradually down the valley axis. 
A study of suspended sediment in and near the surf zone has been 
initiated. It is planned to sample suspended material in situ both by 
pumping and by introducing a measuring instrument into the suspension. A 
photometric technique similar to that used in studies of back scattering in 
the atmosphere is being considered. 
A report, "Areal and Seasonal Variation in Beach and Nearshore Sediments 
at La Jolla, California" was published as Beach Erosion Board Technical 
Memorandum No. 39. 
IW New York University, Contract No. DA=49-055-eng-32, Third 
quarterly Report, September 8, 1953. 
Hindcast Data. Dr. Neumann and Mr. James have prepared a paper on the 
methods they are using to make hindcasts for selected points on the east 
coast. ‘The procedures they are using are extensive, detailed and complete. 
Wave Analyser. The wave analyser is finished and it has been calibrated 
against speech records and artificial signals. It has yet to be tested on 
some actual wave records, but with the general increase in wave activity on 
the east coast some tape recorder wave records should soon be available for 
this last step. 
One additional change in design is contemplated in which the recorder 
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