George Baehtold, age 8, of Salt Lake City, Utah, for his question:
How did the salt get in the sea?
Please do not feel disappointed if you also asked this question. It is a very popular subject and only one person can be selected. All the rest of you have a chance to write and ask Andy another question. In fact, you have as many chances left as there are waves in all the oceans.
The rivers are fresh water and they all flow into the sea. In fact, the rivers and the fresh rains keep the oceans filled with water. But as soon as all this water gets into the sea it becomes salty. There is enough salt dissolved in the sea to bury the whole of America a mile deep. What’s more, the sea is getting saltier all the time. Also dissolved in the sea are other chemicals and even metals. There are millions of dollars worth of gold, silver and magnesium dissolved in the sea.
Actually, this is the greatest robbery story in the history of the world. It has been going on since time began. We know the criminals but we cannot stop them or put them behind bars. All these salts, chemicals and metals in the sea were stolen from the land.
The criminals were raindrops, little streams and rivers. Running water is the greatest of thieves. It laps at stones and solid rocks with greedy little tongues. Certain chemicals dissolve in water. Stir a little salt in a glass of water. It disappears. Actually it has dissolved in the water. This is what happens to salts and other chemicals in the rocky ground.
A good deal of rain water seeps into the soil and down through the rocks. Some rocks are porous, full of little holes like a sponge. The water licks its way through pores, through cracks and crevices. It licks at the salts and other chemicals in the rocks, dissolves them and carries them away.
The water in the soil gathers in springs and underground streams. It breaks out to join the streams on the surface. Countless little streams gurgle downhill to join a flowing river. Each carries a load of chemicals it stole from the ground. All this loot is poured into the flowing river.
Compared with the sea, the river water is fresh and free of salt. Nevertheless, it does carry a load of dissolved chemicals. It flows on and on, gathering more and more streams: Finally it dumps its water with its load of salts into the sea.
Once the sea gets the loot, it never lets go. Water evaporates from the surface. But the salt stays behind. Meantime, the rivers are endlessly adding more salt to the sea. This robbery has been going on day and night for hundreds, thousands and millions of years.
All this time, the sea has gathered a little more salt with each passing year. Sea water is getting more and more salty all the time. There is nothing we can do to stop It. For no one can stop running water from stealing salt and other chemicals as it runs over the land.