The Challenger deep

Most people are familiar with the highest point on Earth, Mount Everest.

But the lowest? The deepest?

The place in question is called the Challenger Deep, located in the pacific ocean. It is a strange world of extremes we scarcely see elsewhere.

So don on your diving gear and dive down into the deepest point on Earth.

Deep thoughts

When we think about oceans, we think of its beautiful surface, beaches, and boats.

However, there are all kinds of terrain at the bottom of the ocean like we see on land; there are mountains, valleys, and even volcanoes.

There are also large canyons, like the Grand Canyon in Arizona.

The largest underwater canyon is located near the island of Guam and is called the Marianas Trench.

By Kmusser*

The Marianas Trench is the deepest underwater canyon in the world, and its deepest point is the Challenger Deep – 35,768 feet or 6.7 miles below the surface. To put this in perspective, you could plop the whole of Mt. Everest in there and its top would still be over a mile underwater!


Let's learn some more about this place.

Baby, it's cold outside

It is a fact that it gets cold inside the ocean, and the deeper you go, the colder it gets. Here, in the Challenger Deep, the water becomes like ice water, being just a tad over freezing.

Into the night

Based on most of our experience with water, we would call water clear – you can easily see through it, no?

But water does block some light, especially if there is a lot of it. And if there is something in it (such as sea salt), this becomes even more so. You can see this by looking at the ocean from the air – notice the sea is blue, and you cannot see clear to the bottom.

So as one descends deeper into the ocean, sunlight has a harder and harder time getting through. It gets darker.

So what does the world look like at the bottommost point on the ocean? Take a look at the simulation below.

It is a world of forever dark.

No pressure, please

Dive into a swimming pool

You feel the pressure of the water, especially as you dive to the bottom.

This is only natural; as you go down deeper into the water, the increased weight of the water above you presses down on you more and more.

Now take the pressure you feel at 6 feet underwater, and imagine going down over 6 miles! The pressure down there is about 8 tons per square inch.

Let's put it this way.

Suppose there was a tiny postage stamp down there.

The surrounding water would squeeze it with the same force as the weight of three mid-sized pickup trucks.


Uncovering deep, dark secrets

The name of this deep spot comes from the HMS Challenger. In 1875 she was en route to Japan when the ship happened across it. 'tis most fortunate it did, as she was undergoing an exploration of the ocean and so was taking measurements of the ocean depth. Originally, the basic methods had at the time gave a depth of nearly 27,000 feet.

It wasn't until 1951 that a second expedition with the HMS Challenger II took a more detailed investigation. Now the depth was determined by setting off underwater explosions and listening for the echoes off the bottom. They extended the depth here to 35,640 feet.

Up to this time, only measurements of the depth had been taken. Nobody had actually been there. This changed in 1960 with the descent of the Bathyscaphe Trieste.

The Trieste. Most of it is a tank holding fuel – releasing the fuel allows it to rise to the surface. The small ball at the bottom stationed the two-man. They entered from the top and climbed down a ladder to their spot.

Imagine, if you will, what it was like for Jacques Piccard and Lieutenant Don Walsh on board.

You climb into your cramped little space, the hatch is closed, and you begin your dive. Down you go until you go where there is no light – only darkness out your tiny window. The craft plunges into the cold water, and you begin to feel like you've been crammed into a small refrigerator. You hear scary noises. First, it is the sound of the tanks being squeezed by the unbelievable forces from the outside ocean.

Suddenly, you hear a large crack! Alarmed, you wonder if the craft is breaking. Fortunately, all is still well. (Actually, at that depth, even a small leak would let water in very fast, killing almost instantly.) After 5 hours of suspense, they reached the bottom.

They would spend 20 minutes at the bottom. Sadly, their landing stirred up the deep mud on the bottom, and so a good deal of that time was just waiting for things to settle.

But their suspense was not over so soon. There was some concern that, because of all that ocean pressure, they might not be able to release the fuel and return to the surface. Imagine then their relief when they saw the ship heading back up. Another 3 hours and they were back up topside.

Alien life found on … Earth?

These brave pioneers weren't the last to visit this place – others would follow. But what shocked everyone was the discovery that, even in that most life-unfriendly of places, there was, indeed, life.

Of course, there are little microorganisms (bacteria and the like), but also flatfish and shrimp-like creatures that feed on stuff that settles down from up above.

There is, perhaps, a lesson to be learned here.

Even here in a world that is always a freezing night, with pressures powerful enough to crush a truck, there is still life. This message of strength might inspire us when we are in our own Challenger Deeps.

Food for deep thinking, perhaps.

Great books

Twenty Thousand Leagues Under the Sea

Jules Verne's classic tale that inspired the imagination for the development of the submarine.

The year is 1866, and there is strange talk about a sea monster sinking ships. The French professor Pierre Aronnax and his assistant agree to help seek out this monster but instead discovered it is, in fact, an electric submarine built by Captain Nemo. They then travel around the world in this underwater boat.

A great read, but one caution: The book is written as the professor's personal journal, and so he mentions the different sea creatures spotted along the way – far too many at times for my taste. Feel free to skip past some of the more tedious pages.

On the web

Crushing Pressure, Frigid Cold, And Eternal Darkness: Welcome To Challenger Deep, The Deepest Part Of The Ocean

This webpage goes over some of the facts of this fascinating place.

Rolex presents: The Trieste's Deepest Dive (Extended)

This film was produced by Rolex to document the dive of the Trieste.

Inside James Cameron's Deepsea Challenger

This video documents the Deepsea Challenger dive, a later craft to go to the bottom of the ocean.

Challenger Deep video

This video of the Challenger Deep gives a good glimpse of what it is like down there, including animal life.

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