II. INTRODUCTION 



In the past, studies of the variation of physical and chemical proc- 

 esses with environmental conditions have concentrated on that parameter which 

 varies most widely in commonplace experience, namely, temperature » As our 

 explorations move into the ocean depths, knowledge of additional environmental 

 factors will have to increase o In underwater operations the temperature range 

 of interest covers only a few degrees centigrade, whereas the pressure range 

 covers 10, 000 atmospheres . For undersea operations, our knowledge of the 

 pressure dependence of physical and chemical processes should be ideally as 

 complete as our present knowledge of the temperature dependence of these proc- 



Relatively little experimental research has been conducted in the areas 

 of moderately high and high pressure physics and chemistry. Much of the earlier 

 work, it is worthy of note, was prompted by oceanographical and geological inter- 

 ests . 



The importance of detailed knowledge concerning the electrical conduc- 

 tivity of the sea and of the variation of this parameter with concentration, tem- 

 perature, and pressure is widely recognized. As a consequence of The Conference 

 on Physical and Chemical Properties of Sea Water , held at Easton, Maryland, in 

 September, 1958, (1) sponsored by the Office of Naval Research and the Committee 

 on Oceanography of the National Academy of Sciences, the Committee on Chemi- 

 cal Properties recommended "that electrical conductivity be used as a sea -water 

 characteristic, " and the Committee on Physical Properties reported that knowledge 

 of "the effect of pressure on the conductivity of sea water would be useful ." In a 

 paper given at this same conference, D. W. Pritchard of the Chesapeake Bay Insti- 

 tute of Johns Hopkins University noted that the "lack of certain basic information 

 restricts the use of in situ conductivity measurements in deep water for the de- 

 termination of salinity. There appears to have been no investigation of the effect 

 of pressure on the conductivity of sea water. Thus it would seem very desirable 

 to include a study of the pressure effect of conductivity in any program developed 

 to improve our knowledge of the physical and chemical properties of sea water ."('^> "*) 



jSttliur ai.littl^Jnt. 



S- 700 1-0307 



