RP241 The Deepest Place on Earth

 RP241 The Deepest Place on Earth

Between Japan and Papua New Guinea, deep under the ocean, is a split in the earth. That is the mysterious Mariana Trench, the deepest part of the ocean. It has been measured at 11,033 meters deep at its lowest point. Qomolangma, the highest point on land, could be dropped into it and still have thousands of feet of sea water above it.

Pressure builds as you go deeper under the sea. The weight of water presses harder and harder. In the Mariana Trench, pressure reaches 16,000 pounds per square inch at the bottom. No human could ever survive it. Humans have, however, landed on the bottom of the trench. The *Trieste*, a U. S. Navy bathyscaphe ("deep boat") reached the bottom in 1960 with two men on board. It had been carefully designed to withstand the intense pressure. Still, the two men who went down in it must have been nervous!

Other creatures, however, can tolerate some of the pressure. Strange things live in the Mariana Trench. Light can only penetrate about 1,000 meters into water; after that, life is in the dark. Some fish make their own lights. The anglerfish has a bobbing, bioluminescent light dangling on a stalk over its head. The light shows other fish the way to their doom. The light hangs right over the anglerfish's nasty jaws. Fish that approach it get snapped up quickly.

The viperfish also has a light embedded in its body. It turns the light off and on to attract prey or a mate. Like the anglerfish, the viperfish uses light to lure meals to its mouth.

These fish can't reach the lowest depths, but mud samples from the bottom are full of microorganisms that can withstand the awesome pressure. As the last time humans reached the bottom was in 2012, the microorganisms will probably be able to live in peace for a long while yet.