Andy explained the ground watery the large reservoirs of water buried in the rocks below our feet This ground water is a peat of the vast, global water cycle which provides all living things with a constant supply of fresh water A cycle, of course, goes around and around with no beginning and no end In nature there is also an oxygen cycle, a carbon cycle, a nitrogen cycle and many other round abouts which supply needed minerals to the plants and animals
A brisk shower can drop an inch of rainfall in half an hour* An inch of rainfall over one acre weighs 113 tons When Pennsylvania gets a drenching from one inch of rainfall, it means that more than two billion tons of water have been dumped on the state The average downpour of rain and snow far the state is 42 inches ‑ about 80 billion tons of moisture
Some areas around the world have more and some have less rainfall At any moment, there are showers and storms over some part of the earth 1s surface, What happens to all this water? It moves to the next stage of the water cycle Some runs down sloping hills and over hard, rocky ground in giggling little streams The streams meet each other on the way and finally loin to form grew rivers The rivers swish their watery skirts and wind lazily down to rendezvous with the sea There they dump the runoff part of the rainfall
Some rainfall sinks into the soil where it waits to feed the thirsty plants Some sinks down deeper to porous rocks There it is held trapped in great reservoirs of ground water Some of this water breaks forth in bubbling streams and some in steamy geysers The runoff from springs and geysers also wends its way to the rivers
The destination of the rainfall and the melted snow is the ocean, though
on, the way some of it is used by the plant and animal world
The next stage of the water cycle takes place on the face of the sea, on the lakes and rivers, the puddles and even the laundry on the line The sun beams down and dries up the moisture, turning liquid water into vapor, The vapor rises up to mingle with the other invisible gases of the air Chances are, the air is warm and warm air tends to expand and rise This newly made vapor rides up, as it were, on an elevator powered by the sun
The next stage is a flying carpet ride As the warm air expands, it becomes cooler and cool air can hold less moisture, `It must give up some of its vapor and it does so by turning it back into tiny droplets of water A cloud is born For a while it floats in the air, moved by the breezes like a flying carpet over land and sea,
Gradually the weather conditions aloft change The cloudy droplets become bigger, too big and heavy to float in the air, And down comes the rain The rain will fall far, far from where it was first gathered up by the beaming sun and a distant part of the thirsty ground will be quenched Now we are bank to the rainfall and the water cycle starts all over again