Chta-Shun Yth 
DISCUSSION 
Michael N, Yachnis 
Naval Faetltttes Engineering Command 
Washington D.C. , U.S.A. 
It seems to me that ''boundary waves" or ''inter-face waves" 
are more suitable terms for two or three layers of fluid that the term 
"internal waves''. I have four basic questions associated with the ap- 
plication of Professor Yih's Paper, especially on actual ocean intern- 
al waves: 
1. Possibility of short internal waves and breaking pheno- 
mena. 
2. Interaction between surface waves and internal waves. 
3. Effects of internal waves on fixed or moving structures, 
4. Influence of earthquake or disturbances of the bottom of 
the channel on internal waves. 
REPLY TO DISCUSSION 
Ceo... Lan 
Untverstty of Michtgan, 
Ann Arbor, Michtgan, U.S.A. 
I have been asked by Dr. Yachnis to comment on four matters. 
This is a great compliment. I do not know that much, but I shall try. 
Iam glad he mentioned short internal waves. I forgot to men- 
tion short internal waves propagating along a channel of variable depth 
in the direction of the axis. If you do not have stratification, very 
short waves are not terribly interesting, for this reason : if the den- 
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