Seven months after Malaysia Airlines Flight 370 took off, there’s no trace of it or any of the passengers. It’s believed that it went down in unmapped waters, off the west coast of Australia.
One of the reasons we haven’t been able to find it is we that we know very little about our aquatic territory. It’s more alien to us than the surface of the Moon. We’ve explored a mere one percent of the “deep ocean”—that is, the column of seawater that lies below 650 feet.
It remains mysterious because of its vastness and depth. Plumbing every 33 feet, scales up the water pressure by one atmosphere. The load at the Challenger Deep in the Mariana Trench, which, at nearly 36,000 feet below sea level, is the deepest known depression in the ocean, is colossal. Even fish can’t survive beyond 27,000 feet.
Making submersibles that can endure the crushing weight of the water on the seafloor presents another challenge. So, they’re typically, made of titanium, and are round or curved as flat surfaces would cave in easily.