70 FRONTIERS IN OCEANIC RESEARCH 



underwater distance of about 20 miles. This is actually a renewal of 

 an attempt to build such a tunnel about 85 years ago. Generally, the 

 pressure of increasing traffic and the financial success of toll road oper- 

 ations should help revive the demand for underwater tunnels in places 

 where bridges are not practical. 



Underwater communications probably will be used on a modest scale 

 and in special situations since radio has overtaken the underwater 

 cable for general transoceanic use. For example, undersea cables may 

 be useful in and across the Arctic where magnetic disturbances seri- 

 ously affect most other f orms of communication. The nuclear-powered 

 submarine now gives us the technical capability to lay a cable beneath 

 the Arctic ice if this becomes desirable. Some day in more peaceful 

 times, we may see a substantial network of direct undersea communica- 

 tion between the United States and liussia across the polar region. 



FRESH WATER CONVERSION 



Conversion of sea water into fresh water is one of the outstanding 

 areas of technical development today. Several methods are physically 

 practical so that the chief problem is to .reduce operating costs to a 

 competitive level with natural sources of fresh water. At present the 

 Department of Interior's Office of Saline Water is sponsoring five 

 pilot plants, each working on a different principle and all located in 

 different parts of the United States. 



One such plant will be located in southern California, will consist 

 of a nuclear reactor as a source of heat, and will distill fresh water 

 from sea water at a rate between 1 and 2 million gallons per day. 

 Others will use freezing or electrical methods of removing impurities. 



Implications of this line of development are tremendous, since new 

 areas of the world may be opened up for settlement and improvement. 

 Nuclear power will give impetus to the whole movement, not only in 

 yielding process heat, but also as a source of power in pumping water 

 uphill from sea level to the consumer. 



MINING AND CHEMICAL EXTRACTION OF MINERALS 



Thus far, undersea mining has been accomplished most extensively 

 by the oil industry. The technical skill and daring which has been 

 displayed by that industry is one of the engineering feats of our time. 

 Oil is a logical subject for undersea exploitation because it is easier 

 to locate and handle than solid minerals. 



The latter, mining of solid materials from the ocean floor is begin- 

 ning to resemble offshore oil drilling. The Grand Isle Sulphur Mine 

 in the Gulf of Mexico will soon operate from a very large and elabo- 

 rately equipped steel tower structure. Among other noteworthy fea- 

 tures, the plant will use hot seawater in the process of melting and 

 handling the sulfur. Also, the hot sulfur- bearing liquid is transported 

 7 miles to shore through a heated pipeline. 



Development of other undersea mining is still largely exploratory. 

 Perhaps the next step will be to recover manganese and cobalt from 

 the so-called manganese nodules which have been discovered in 

 large numbers on the ocean floor. 



We now turn to a different type of mineral exploitation ; namely, the 

 extraction of minerals directly from sea water. 



