48 MARINE SCIENCE 



You point out in a lO-months cruise of one vessel, a great numiber 

 of programs are undertaken. In other words, the soup is getting 

 too thin on some of them, isn't that right. 



Mr. WoRZEL. We don't feel justified in sending a ship around the 

 world without their undertaking as many programs as can be sup- 

 ported on the ship. The limitation is on the size of the ship and 

 her space for scientists. 



The Chairman. Also, Dr. Ewing's statement will be put in too. 

 It refers to seismic refraction at sea. If you will explain that briefly 

 to us we will put this in the record, of course. 



Mr. WoRZBL. Do you wish me to read the statement? 



The CHAiRMATir. You can summarize it and we will put it in in full. 



Mr. WoRZEL. In seismic refraction studies one fires an explosive 

 from one ship and listens to the sounds which travel through the 

 body of water and through the various layers in the bottom of the 

 ocean to another ship at distances varying between a few miles and 

 up to 60 miles. These studies are of importance geologically in un- 

 derstanding the structure of the ocean bottom. From them we can 

 determine the velocity of sound in the layers beneath the bottom 

 and the thickness of the layers and we can then make reasonable 

 judgments about the type of materials that are in the layers. In 

 essence, seismic refraction is an "X-ray" technique for looking at 

 the bottom of the ocean. 



In the course of this work, it is necessary to determine the velocity 

 of sound in the water layers throughout the ocean. This study led 

 Dr. Ewing to his thoughts about the sound channel. 



Seismic studies at sea were the forerunner to the development of 

 techniques which the petroleum industry now uses in their offshore 

 exploration work. They have taken our work and extended on it 

 for their own purposes. 



The Chairman. Then Dr. Ewing also points out the great amount 

 of good will that has come from all of us working together, with 

 some of the other people in the free nations, and I suppose a lot 

 is due to the International Geophysical Year too. From that we have 

 found out a few things. 



Mr. WoRZEL. Yes, sir. 



The Chairman. It has some international aspects too because the 

 seas are international. 



Mr. WoRZEL. Oceanography both benefits by and contributes to 

 international cooperation. 



If you will notice the paper entitled "International Relations," we 

 have worked with our ships, cooperatively with the ships of the fol- 

 lowing nations: Chile, South Africa, Spain, Brazil, Argentina, and 

 Australia. 



In addition to this, we have entertained on board our ships, and the 

 other institutions have done likewise, 15 Argentinians, 8 Italians, 6 

 South Africans, 5 Chileans, 5 Spaniards, 4 Germans, 4 Peruvians, 4 

 Australians, 4 Turks, 1 Greek, 1 Hollander, 1 Algerian, 1 Japanese, 

 and 1 Bermudian. 



The great diversity of nationalities that are on our ships raises a 

 great interest in the foreign ports that our ship touches and invariably 

 there is an item in the press favorably extolling the international 

 cooperation that is exhibited by just one of these small ships operating 

 in this way. 



