Sec. 4R.17 



WIND-WAVE AND SHIP-WAVE DATA 



18] 



Table 48.1 — Comparison Between Characteristics op 

 Shallow-Water and Deep-Wateh Waves 



48.16 Shallow-Water Wave Data. The rela- 

 lationship between the velocity or celerity c and 

 the wave length L^r for various uniform depths h 

 of shallow water of unlimited horizontal area is 

 given in Figs. 48.0 and 48. P, adapted from D. W. 



Taylor [S and P, 1943, Figs. 11 and 12, p. 12]. 

 Somewhat the same data are given in graphic 

 form, but in metric units, by 0. Schlichting 

 [STG, 1934, Vol. 35, Fig. 3, p. 130; EMB Transl. 

 56, Jan 1940, p. 4]. 



Sir Horace Lamb gives a table relating the 

 wave length Lw , the wave period T^ , the celerity 

 c, and the shallow-water depth h, for lengths of 

 1, 10, 100, 1,000, and 10,000 ft, and for depths of 

 the same amounts [HD, 1945, p. 369]. 



For information. Table 72. a in Sec. 72.3 pre- 

 sents a list of speeds for a solitary wave or a 

 wave of translation in shallow water of uniform 

 depth. The range of water depth is from 2 through 

 40 ft and the celerities are given in both ft per 

 sec and kt. 



48. 1 7 General Data for Miscellaneous Waves ; 

 The Tsunami or Earthquake Wave. Scientists, 

 mariners, and others have from time to time 

 studied the behavior of waves other than those 

 caused by natural wind. Among these is the 

 tsunami, or earthquake wave, generated by a 

 sudden vertical displacement in the earth's crust, 

 usually under the ocean or close to the coast. A 

 gigantic earthquake wave would probably pass 

 unnoticed by a ship in the deep, open sea but 

 over a shoal bank or near the shore it might spell 

 disaster to any vessel. 



It is reported that some earthquake waves have 

 traveled at speeds of 600 miles per hr [Votaw, 

 H. C, "Our Navy and South America's Greatest 

 Earthquake," USNI, Mar 1948, p. 345]. It is 

 reported also that an earthquake wave can have 



-^5 



50 100 150 200 250 300 350 4W 450 500 550 600 650 700 750 



Wove Len(^th L^ , ft 



850 900 950 1000 



Fig. 48.0 Relation Between Wave Length and Wave Velocity in Various Depths of Water 



