Although Table 3 can be basically summarized as "significance 

 unknown," two locations for many of the reactions are suggested which 

 have been little studied from the point of view of controlling mechanisms 

 of major seawater constituents. These are the continental margins and 

 the photic zone. We should (1) carefully investigate these areas using 

 new field techniques such as in-situ sensors, (2) characterize the highly 

 reactive, amorphous phases, and design experiments to study their 

 thermodynamics and kinetics, and (3) consider and experiment in the 

 field and the laboratory on the possible effects of organisms on major 

 constituents, as well as conventional nutrients and organic phases. 



The Physical and Chemical Properties of Seawater 



The bulk thermodynamic and transport properties of seawater (such 

 as P-V-T data, viscosity, conductivity, specific heat, enthalpy, freezing 

 point, sound absorption, etc.) are useful to describe physical oceano- 

 graphic processes such as adiabatic mixing and deep sea stability. 

 Although numerous measurements (Pytkowicz and Kester, 1971; 

 Millero, 1973a,b) have been made on the physical properties of sea- 

 water, there still is a need to reconcile the differences that exist between 

 various investigators. For example the P-V-T properties (the equation 

 of state) and the sound absorption of seawater need further work. There 

 is a need for a reliable equation of state for seawater for deep-sea stability 

 calculations. One method of deriving a reliable equation of state for 

 seawater is to calculate compressibilities from sound velocity and specific 

 heat measurements by an iterative technique (Crease, 1962). Since one 

 can measure sound velocities with great precision, and the difference 

 between adiabatic and isothermal compressibilities is small, the com- 

 pressibilities derived from sound velocities are more precise than those 

 determined by direct methods (Fine, Wang and Millero, 1973). Unfor- 

 tunately, the velocity of sound measurements made by Wilson (1960) 

 and Del Grosso and Mader (1972) are not in good agreement at high 

 pressures and low temperatures (the oceanographic range of importance 

 for deep-sea stability calculations). These discrepancies must be rec- 

 onciled before we can derive a reliable equation of state. Direct mea- 

 surements on the P-V-T properties of seawater with accuracies ap- 

 proaching those of sound velocity measurements (Millero, Knox, and 

 Emmet, 1972; Emmet and Millero, 1973) would also yield useful data. 

 It is important that all the P-V-T properties (as well as the other physical- 

 chemical properties) of seawater be directly related to pure water. The 

 reason is twofold: first, pure water is the working standard for the 

 P-V-T properties of liquids, and if corrections are needed in the future 

 they can be made; second, and probably more important, by examining 



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