Air Date: Week of November 28, 1997

This week, facts about... the deepest ever submersible dive.

Transcript

CURWOOD: It's not 20,000 Leagues Under the Sea, but it's as far as divers are likely to go. In 1960, Swiss scientist Jacques Picard and US Navy Lieutenant Don Walsh plunged deeper into the ocean than anyone before or since. The 2 men descended nearly 7 miles to the bottom of the South Pacific, the Marianas Trench, then the deepest known spot in the ocean. Messrs. Picard and Walsh made their historic trip in a bathyscaphe, a vessel which consists of a small spherical chamber attached beneath a 28,000-gallon tank of gasoline. Iron weights sank the vessel. To resurface, it dropped the weights, and the gasoline, which is more buoyant than water, floated the ship back up. It took the explorers 5 hours to reach the bottom, 2.3 leagues under the sea. They collected mud samples with mechanical arms and started back up to the surface after just 20 minutes. And who could blame them? At that depth, water pressure is over 8 tons per square inch. That's like having 48 jumbo jets on your shoulders. And for this week, that's the Living on Earth Almanac.