Physical and Chemical Oceanographic Parameters 



For design of the bottom structure and analysis of its maintenance 

 and functional requirements, measurements must be made for currents, tem- 

 perature, salinity, dissolved oxygen, pH, and hydrogen sulfide. The patterns 

 of the water currents at each site are required for design and stability analysis 

 of the structure to be placed on the seafloor. The magnitudes, direction, and 

 average duration of the currents are required to design for lateral loadings on 

 the structure and on foundation elements. Currents would generally tend to 

 displace laterally and overturn the structure and create scour and fill problems. 

 Thus, an assessment of the currents must be made for each site. 



Data on the other physical and chemical oceanographic parameters 

 including temperature, salinity, dissolved oxygen, pH, and hydrogen sulfide 

 are required for designing the bottom structure and for making a proper eval- 

 uation of its maintenance and operational requirements. The foremost reason 

 for measuring these properties is to evaluate the corrosion potential of the 

 particular site. Knowledge of these properties together with various in-situ 

 test data 7,s will aid in the design of corrosion-resistant structures for longer 

 maintenance-free installations. Since corrosion decreases the safety factor of 

 the structural members, it is important that these site parameters be measured 

 so that a proper design can be achieved. 



The measurement of these parameters is also required to make an 

 assessment of the suitability of the site for the intended purpose of the bottom 

 structure. For example, if the intended purpose of the structure is to conduct 

 research on sound velocity characteristics, the site with the best physical prop- 

 erties to conduct this study can be selected. If aquaculture studies are the prime 

 objective of the bottom structure, the site with the environment most conducive 

 to the successful conduct of these experiments would be desired. In addition, 

 the water temperature and salinity at respective pressures are used in the correc- 

 tion of the depth determined by a sonar technique in the bathymetric surveys. 



Biological Oceanographic Parameters 



Biological characteristics influence marine fouling and destruction, 

 visibility, and sound transmission at a given location. It has been shown by 

 various researchers (for example, Muraoka 9 " 15 ) that fouling and destructive 

 effects of structural components due to biological activity would definitely 

 be a problem at water depths to 6,000 feet and, possibly, deeper. Attachment 

 of large quantities of fouling organisms on structural components would be a 

 problem in the upper few hundred feet of water. These fouling effects decrease 

 with depth; however, marine borers and microorganisms are still present to 

 cause destruction of materials associated with the structure at greater depths. 



