Not so long ago, our old earth was given a thorough physical examination by teams of scientists from 66 different nations. The time taken for the work was 18 months and this remarkable event was called the International Geophysical Year. The scientists, working together, made some startling new discoveries about the planet on which we live. The floor of the ocean was explored and for the first time we have a chart of the entire sea bed, somewhat like the maps which show the ups and downs on the dry land.

The blue waters of the Pacific Ocean cover one third of the globe on which we live. If we were in a space ship miles above the center of the Pacific, the earth would look like a very watery world. Along one rim of the globe, we would see the edge of the Americas and here and there perhaps a few small islands. This space ship view gives an idea of the size of the Pacific Ocean which, in cold figures, covers an area of 64 million square miles.

We also can give the average depth of the great Pacific in cold figures. But unless we form a picture in our minds of the ocean floor, these figures do not make much sense. For the solid sea bed has far more ups and downs than a trip from Spokane to Denver. The average depth of that vast area must take into account deep ditches, towering mountains and sloping plains p all far below the surface of the blue Pacific.

Where the land meets the ocean, the shallow water may be only a few inches or a few feet deep. But as we leave the land, the floor of the sea dips lower and lower. This gently sloping region is the Continental Shelf which surrounds all the land masses.

At a depth of perhaps 600 feet it plunges in a steep cliff to the true floor of the sea, the abyss which we call the ocean basin.

The basin of the Pacific plunges more than two miles below the surface. Down here, where everything is blacker than blackest midnight, the ocean floor is wrinkled with mountains and gashed with still deeper ditches. Some of the peaks are a mile below the surface, some of the ditches are more than six miles below the surface and some are thousands of miles long.

There are wide plains and hundreds of underwater volcanoes and some of the mountains on the ocean floor are high enough to poke up as islands. With all these and many other ups and downs, we can give only a rough estimate of the depth of the Pacific Ocean. Most experts agree that this average depth is about 14,000 feet   which is somewhat less than three miles,

The survey of the IGY discovered a vast range of undersea mountains in the South Pacific. Most of their peaks are almost two miles below the surface and the range loops around South America to link up with a vast chain of mountains reaching down the middle of the Atlantic Ocean.