Deep oceans refer to areas away from coasts that are beyond continental shelves, where the seafloor drops to extreme depths below 10,000 feet. Life exists in these extreme environments where there is almost no light and freezing temperatures. Natural inhabitants feed off debris that drifts down or eat each other, and many live around hydrothermal vents. Humans are beginning to explore and mine resources from these environments, but the high pressure and lack of oxygen pose risks to human physiology.

2. What are Deep Oceans? Any Place away from the coasts & beyond the continental shelves, where the seafloor drops to extreme depths. Why Study/Explore Deep Oceans? Some humans are preparing to mine the thick crusts created by geothermal vents for Gold, Silver, and Copper The water is used for recreation, such as scuba diving, and warfare using submarines

3. What Makes this Environment Extreme? Almost no light penetrates Nearly freezing temperatures Under more than 10,000 feet of water life still exists

4. Natural Inhabitants Animals feed off of debris that drifts down from animals in the upper layers of the ocean, or they eat each other. Many live around hydrothermal vents (“Black Smokers”), feeding off of the bacteria that live and feed in the mineral-rich water coming out of the vent No light penetrates this far down into the ocean, and many animals have huge eyes to see.

5. Deep Ocean Firsts In the 1930’s, William Beebe and Otis Barton designed a Bathysphere and used it to dive 3028 ft/922 m underwater In 1620, a Danish doctor, Cornelius Van Drebbel designed and built the first workable submarine that could travel to depths close to 15 feet The Challenger Expedition covered 127,653 km, and provided the first real view of major seafloor features

6. Underwater Records Accomplished free-divers, such as Umberto Pelizzari, can stay underwater for 5 minutes, and go underwater as far as 200 ft The deepest a free-diver has gone is 417 ft The deepest a SCUBA-diver has gone is 475 ft, or 145 m

7. Affects on Humans The most highly affected human body systems are: -RESPIRATORY -CIRCULATORY -NERVOUS

8. Effects on the Respiratory System Human lungs are adapted for gases at 1 Atmospheric Pressure, which is the pressure of the air on land The lungs are not capable of breathing water, in part because of the difference in pressure, and mostly because water contains very little dissolved Oxygen, which is required for the human body to function Without special equipment, humans will die underwater from lack of oxygen

9. Effects on the Circulatory System The “Bends” is a term used to describe what happens to SCUBA divers if they ascend to the surface too quickly When divers inhale the compressed air, the nitrogen in it dissolves into the blood If divers ascend too quickly, the nitrogen forms bubbles within the blood, and if the bubbles are large enough they can get stuck in the body’s capillaries and block blood flow

10. Effects on the Nervous System Nitrogen is one of the main parts of compressed air found in air tanks used for diving, and becomes an anesthetic at 100+ ft below the surface of the water Inhaling too much can cause effects similar to being drunk, which is called Nitrogen Narcosis Oxygen is also toxic at high pressure, and can affect the central nervous system (the brain and spinal cord), causing seizures underwater

11. Special Clothes/Equipment Water takes heat away from the body 25% more than air does A “Wet Suit” traps a thin layer of water against skin, to keep the skin insulated A “Dry Suit” traps a layer of air against the skin to keep the skin insulated In order to breathe underwater, either an air tank containing compressed air is needed, or a submersible that can maintain an internal pressure of 1 atmosphere

12. Deep Sea Submersibles “ Jim Suit”: a 1 man, 1 atmosphere, armored suit which can work for hours at 2000 feet or more underwater Alvin was the first deep sea submersible, and was a 3 person, self-propelling submarine, which was nearly 8 meters long The Shinkai 6500 was a Japanese Research submarine built in 1989 that could travel to depths up to 6,400 m In 1960, Jacques Piccard and Navy Lieutenant Donald Walsh went down to the deepest part of the Pacific Ocean, the Challenger Deep (Marianas Trench), which is 36,201 ft, or 11,033 m deep. They used a submersible named Trieste