T.M. No. 58 (Continued) 



are included. The instrument analyzes a 20-minute wave record in 

 approximately three minutes and records the resulting power spectrum 

 on chart paper. 



T.M. No. 59 - February 1955 



Laboratory Study of Shock Pressures of Breaking Waves by C. W. Ross 



Results are presented of a laboratory study to investigate the 

 h igh- i ntensity shock pressures on structures as contrasted to the 

 much smaller hydrostatic pressures developed by rise of the wave 

 against the face of the structure. The laboratory waves were from 

 3.5 to 7.5 inches in height, producing maximum observed shock 

 pressures of 21 psi. Data were insufficient to establish definitely 

 the relation between pressure and wave height, but an approximate 

 linear relationship is indicated. 



T.M-. No. 60 - January 1955 



Generalized Laboratory Study of Tsunami Run-up by Kenneth Kaplan 



Results are presented of a laboratory study made on generalized 

 beach and structure shapes for the relation of tsunami runup to the 

 characteristics of the wave. It is found that the relative runup 

 can be related to the wave steepness, and relationships are evalu- 

 ated for certain slopes and structure types. For Hilo Bay, Hawaii, 

 this study indicates that a runup of at least two wave heights at 

 the shoreline is possible. 



T.M. No. 61 - August 1955 



Laboratory Study of Wind Tides in Shal low Water by Osvald J. Sibul 



Laboratory tests were made to enable some quantitative interpre- 

 tation of bottom effects, water depth and wind strength on wind tide 

 (setup). Experiments were conducted with smooth and rough bottom 

 conditions. Results indicate a rapidly increasing setup when still 

 water depth decreases below a certain limit. There were no indica- 

 tions that bottom roughness affects setup for relatively deep water, 

 however, rougher bottom conditions result in very shallow water. 

 The trend is especially pronounced for higher wind velocities. 



18 



