THE EARTH’S WATER.

Taranaki Daily News, 22 November 1930, Page 9 (Supplement)

THE EARTH’S WATER.

Have vou ever wondered how much nater there is i»i the. world, and whether it ever gets any more or less? When you see how the hungry, waves cat into ■ the cliff®, and rivers in flood widen their you. may think that the land is on' the losing side. Well, the land is not destroyed, it' is just covered over by the sea and becomes sand, or else is deposited on the river bed. So although in thousands of years the sea may cover more land than it does now, it is doubtful whether the amount of water will increase very much. , ~ Men have estimated that at the present time the five great oceans have a ■- surface area of 14?,000,000 square miles, ■ and an average depth of two, miles and ' . a half* 'Then, there is the water in lakes

and rivers, which is about 1,000,000 cubic miles. ' Also do not forget the large quantity of water in the ground and the atmosphere, which is estimated at 3 000,000 cubic miles, making the grand total of 335,000,000 cubic miles of water in and on the earth. . One way of illustrating this amount of water is to imagine it pumped into a, huge tank. You would have to build it 694 miles in length, breadth and height to hold the water. If one corner of the tank were placed in Auckland, the other corner would reach beyond Wellington. But having got the water into the tank it would be a big job to get it out again. A pipe with the capacity of Niagara carrvim' awav 200,000 cubic feet ot water a second would take 17,000,000 years to return the water to its light ocean, lake or river.