Water is found everywhere, from high in the atmosphere to very deep within the rocks underground. It covers about 71 percent of the earth’s surface. People use it constantly, all day long, every day, but water has a few secrets you may not be aware of.
Just like the air you breathe, water creates pressure. High in the atmosphere there is very little oxygen, and you would die there. The air down on the earth’s surface is under more pressure from the air above it, and so there is plenty of oxygen per square inch, letting you breathe freely. Similarly, when water is placed in a container like a pool or an ocean, the water at the bottom is under pressure from all the water above it. Think back on how your ears felt the last time you tried to swim to the bottom of a deep swimming pool.
Water pressure has the ability to crush things. Water a few feet deep, rushing down a stream bed or culvert, can create hundreds of pounds of pressure, making it impossible for humans to resist the flow or push themselves away from objects they may be pushed up against. This may make you seem puny in comparison to water’s strength, but this is just the beginning. Most submarines can only go a few thousand feet deep into the sea. If they venture further, they will leak and be crushed. It is said that at the depth of a few thousand feet in the ocean, a submarine would not simply flood and sink, it would be instantly crushed and torn into small fragments. This is how violent the water pressure is at that depth. At depths of around 4-5 miles (around 22,000-26,000 feet) found in the deepest ocean trenches, water pressure can be more than 8 tons per square inch or around 8,000 tons per square yard. This is equivalent to more than 1,600 elephants standing on the roof of a very small car, or one person trying to hold back 50 jumbo jets. There are no bathyspheres (very specialized subs) that can go this deep but special cameras have been lowered to this depth, and they have discovered abundant sea life. It is surprising that animals can exist at this depth at all. Also surprising is that this is not the deepest part of the ocean trench; the deepest parts are around 7 miles deep and have even higher water pressure.
There are some environments where water may be placed under even higher pressures. Jupiter’s mass is about 15 to 20 times the mass of the earth. If water is placed under enough pressure, it would become super hot, and yet it would remain a liquid because the pressure would prevent its boiling off as steam.
Uses of Water Under Extreme Pressure
Tools using high-pressure jets of water can cut cement pipe or sheet metal.