The Oceans^ 

 Their Structures and Features 



One of the rarest things in our solar system is 

 water. As far as we know, only the planet Earth has 

 free water, and on earth there is an abundance of this 

 compound. In fact, if it were not for the irregularities 

 of the continents and ocean floor, our globe would be 

 covered by 12,000 feet of ocean. Yet, man generally 

 ignores this fact. He emphasizes the 29 per cent of 

 the surface that is land — an emphasis indicated by 

 the name of our planet . 



Man should not overlook the fact that the ocean, 

 like each of the other physical aspects of our planet, 

 is "essential to life as we know it." Before treating the 

 properties of water, the landscape of the ocean floor, 

 and hydrologic movements in the form of currents, 

 tides, and waves, we should consider those qualities 

 that make water essential to life on earth. 



A planet provides, among other things, an environ- 

 ment that is an either-or condition for any form of 

 life. Either the life can live within the provided en- 

 vironment, or it cannot. Earth provides, among other 

 things, carbon, water, and air. The element carbon 

 has the necessary chemical properties to allow life 

 processes. The importance of air was already men- 

 tioned, and that of water soon will be mentioned. 

 Moreover, it is logical that the chemical processes of 

 life involve materials that are both available and suit- 

 able. In other words, if organisms occur, they must 

 be intimately associated with their environment. 



A logical question is, "Would all life require a 



carbon basis like that upon earth?" The answer 

 probably is No! Because life is a chemical process 

 and other chemical elements have a number of the 

 essential properties of carbon, it is possible that other 

 bases for life — even intelligent, generally humanoid 

 life — could exist. However, they probably could not 

 exist on any of the other planets in our solar system. 



OCEAN WATERS 



Life must have started in the ocean. This hypothe- 

 sis is generally accepted for various reasons, some of 

 which will be considered later. Here it is enough to 

 mention that the body fluids of living creatures are 

 similar in composition to ocean water. At least, the 

 materials in body fluids are generally found within 

 the sea. 



PROPERTIES OF WATER 



Water has properties that are essential to earth 

 life. This liquid is necessary to rnix and disperse 

 chemicals in processes of growth and repair. In 

 man and other mammals, and in birds, a fairly con- 

 stant body temperature is possible, partly because 

 water neither gains nor loses heat rapidly. Water 

 also dissolves more substances than does any other 

 liquid, a characteristic that makes it the nearest 



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