182 



lUMRODV.NAMICb l.N Mill' DLSICX 



Sec. tS.lS 



10 



10 



35 



40 



45 



15 ZO 



Fia. 4S.P Relation Between Wave Lenoth and Wave Veixjcity in Vbhv Shallow Water 



25 30 



Wave Len<^th L^, fl 



a height of 8 ft at 12,000 miles from its origin. 

 If tlie relationship c = \^i held at sea, as in 

 shallow water, a celerity of this magnitude 

 (600 mi:)h) would require a water riepth h of the 

 order of 24,000 ft. 



For earthquake waves traveling across conti- 

 nental shelves of lesser depth the wave velocity 

 appears to be less, but the wave heights are 

 probably greater. David Milne, in a paper 

 entitled "On a Remarkable O.scillation of tlie 

 Sea, observed at \'arious Places on the Ct)asts of 

 Great Britain in the First Week of July 1843" 

 (Trans. Roy. Soc. Edinburgh, 1842-1844, Vol. XV, 

 pp. 609-038, reproduced by permi-ssion of that 

 Society], writes as follows on page 633: 



"(4) The circumstance that the osciUation of the sea on 

 the Ckimish and Devonshire coast preceded the arrival 

 of the storm by some hourx, so far from being an objection 

 to the view above sugj;o.Mt<;d, is rather a conlirniation of it; 

 as it is well known, from tlio researches of Mr. Scott 

 Russell, that a wave, when generated by a moving force, 

 will ucquiro a vi-loeity greater than that of the force 

 producing it, if the depth of water be sufFicicnt. I have 

 elsewhere shewn, that the waves protiuced b^' the Lisbon 

 carthijuakes came to the English and Irish coasts, with 

 a velocity of from 120 to 100 miles an hour. It is therefore 

 probable, that if a wave were generated by the storm in 

 question, it would move forward with about double the 

 rapidity of the storm itself, which, I have shewn, travelled 

 at a rate of only 70 or 80 miles an hour." 



W. Thomsfju (later Ixjrd Kelvin), writing in a 

 paper "On the Rigidity of the Earth" [Phil. 



Trans. Roy. Soc, 1SG3, Vol. 153], states on page 

 581 that the velocity of long free waves, such as 

 those encountered in mid-ocean, in depths of 

 10,000 ft or so, is 507 ft per sec. This celerity 

 corresponds to 38(5.6 mi per hr or 335.7 kt. 



The data collected by J. Turnhull and men- 

 tioned in Sec. 48.8, plus the data published by 

 H. Keeton in The Marine Observer |1930, \o\. 

 VII, pp. 106-113, esp. pp. 109-110], hidicate that 

 single abnormal .seas, like onrusiiing walls of 

 water, are not infrequently encountered in the 

 oceans of the world. No one seems to know their 

 e.xact cause, nor are there many ciuantitati\'e 

 data for the more disastrous of them. It is probable 

 that many ships which have been lost without 

 trace have been the victims of these huge waves. 



48.18 Bibliography of Historic Items and Ref- 

 erences on Geometric Waves. Of the extensive 

 bibliognii)liy on water waves in general, including 

 .sea and wind waves, it is possible onlj' to mention 

 a few of the jirincipal references. The first part 

 of the appended list covers the historical refer- 

 ences, prior to 1900. Unfortunatelj', tlie reference 

 data on some of the early papers are incomplete. 



The references quoted in this section may be 

 supplemented by those of G. C. Manning on 

 pages 48 and 49 of PXA, 1939, Vol. II. 



(1) Qerstner, Franz Joseph, "Theorie der Wcllen (Theory 

 of Waves)," orig. publ. in .Vbhandlungen der 

 koenigl. bueliniisriicii Cic.ti'll.icliaft ilcr \Vi.'(.ti>nHchaf- 

 t<!n /.u I'nig (Trans. Hoy. Buhein. .'^oc., I'rjiguuJ, 



