What is the maximum depth a human can enter earth?

Answer 1

Quote from the Related Link: "The human body, for the most part, is made up of water (60%+/-) and other substances that are approximately as dense as water - with very little gas. What gas the human body does have would get compressed as the body goes further and further down. Specifically, any gas in your lungs, ear (and related canals), blood, and stomach will become compressed. Let's take Scuba diving as a basic intro to how the body and how gasses behave under water. When you dive under water, you'll feel pressure in your ears - this is the air in your ears (and related canals) getting smaller as a result of the water pressure. If you can allow water to enter this space, the pressure equalizes and the discomfort disappears. As the air in your chest compresses, you have less air to breathe - but fortunately, you have an air tank and can add compressed air to your lungs (via breathing), thereby filling your lungs and allowing you to breathe. The reason(s) why human beings don't go to thousands of feet without specialized suits doesn't have to do with getting crushed - it has to do with a few things: 1) The Bends (decompression sickness). When the body is under pressure, it behaves a bit like a bottle of soda. If the pressure is released too quickly, bubbles form in your body (brain, blood, joints). This can result in anything from discomfort to instant death - with anything in between (brain damage, stroke, lung problems, nerve damage, etc). If you go down to say 3000 feet and try to surface, it would likely take a LONG time to decompress appropriately and safely to come back up. 2) Breathing. Oxygen becomes TOXIC under pressure. 21% of air is oxygen - this becomes toxic at depth, so there are different artificial gasses and different levels of oxygen in some tanks, allowing divers to go deeper. The maximum depth that I could find on the internet was @1800 feet. Beyond that, there is no way for divers to breathe. So - in short, you can't/won't get crushed by the ocean - you die because you can't breathe."

Answer 2

From terra firma, roughly 1.5 miles, the depth of the deepest mine in South Africa. The undersea manned submersible ALVIN reaches depths of 14,764 feet below sea level.