Janice Gross, age 11, of Milwaukee, Wis., for her question:
How much gold is in the sea?
There is probably enough of it in the sea to build every family a golden house. There is certainly enough of it there to make everyone in the world a millionaire. However, it is no easy matter to take the gold out of sea water. In fact, it would cost more to take it out than the gold is worth. There have been many get rich quick schemes to rob the sea of its gold, but none has ever paid off.
There was the German chemist Fritz Haber. In 1920 he sailed the laboratory ship Meteor back and forth across the Atlantic with the idea of filtering out gold from sea water. His plan was to use the gold to pay Germany’s war debt after World War I . He soon found that his laboratory ship cost more to run than the gold was worth.
Gold sells at about an ounce. In order to get seven cents worth of it, you would have to process one ton, or 31 cubic feet of sea water. In order to make the fob worth while, you would have to process the water in cubic miles and a cubic mile of water fills a tank one mile long, one mile high and one mile wide.
The problem is that gold is not the only chemical dissolved in the sea. Compared with other substances, there is only a trace of it. Suppose you flooded a small room with sea water a foot deep and then evaporated it. You would be left with about 200 pounds of assorted powdery chemicals mostly salts. Somewhere hidden in the heap would be fine fragments of gold, enough perhaps to cover a nickel. Sifting out the gold would be quite a fob.
In a cubic mile of sea water, it is estimated that there is more or less 1,500 tons of dissolved gold. In the entire ocean, there is about 330 million cubic miles of sea water. This is enough to give us all more than 500 tons of gold with which to build our golden house. Now let's suppose that tomorrow someone invented a quick cheap way to get gold from the sea. No, this would not make us all millionaires. The reason gold is so valuable is because it is rare and hard to come by. If we could take tons of it from the sea, it would lose its value and our golden house would not seem so special.
It is estimated that for every ton of gold in the sea there are 46,100 tons of silver. There is also silvery white magnesium and this light weight metal is being taken from the sea. Along with the assorted salts and minerals dissolved in the sea there are also tans of nitrates and phosphates. These chemicals are valuable soil fertilizers.
How did all this loot get into the ocean? It was stolen from the land by countless little running streams. Water dissolves gold and other chemicals from the soil and rocks and dumps all this loot into the ocean. This biggest of all robberies has been going on for millions of years.