How low can you go?

There’s no doubt that the ocean is huge. In fact, it covers 71% of the earth’s surface, holds 97% of earth’s water, covers 99% of the area that can be inhabited by life, and holds around two thirds of all life on earth. These are some pretty ama-sea-ing stats, but it turns out, we know very little about the ocean! It has been said that less than 10% of the ocean has been explored by humans. We shore have some work to do, but here’s what we do know.

The average depth of the ocean as we know it is around 3800m. Compare that to the average height of land, which is a measly 850m. Turns out, the bottom of the ocean is also not uniform. That means varying depths, mountains and valleys, and to be Pacific, the ocean contains the world’s largest mountain range and deepest canyon.

The deepest place is called Challenger Deep, and is found in the Pacific Ocean’s Marina Trench, formed by the convergence of two oceanic plates. In 2010 it was estimated to be over 10,000 meters deep! That’s one whole mile deeper than Mt Everest is high! It sands shivers down my spine.

Let’s take a dive…

The ocean we know and love is mostly the Epipelagic Zone, AKA the Sunlight Zone. Here is where most of the ocean’s visible light and heat is located. This zone only extends to 200m below the surface.

Next we have the Mesopelagic Zone, or the Twilight Zone, which goes down to 1000m. Although there are no vampires here, the little light that reaches this depth is very faint, and sparkly (or bioluminescent, if I have to be scientific) creatures live here, with some other cool and cra-sea fishes.

Once we dive between 1000m and 4000m below the surface, we’ll be in the Bathypelagic Zone, also known as the Midnight Zone. It’s much cooler here, and the pressure has skyrocketed. The only light at this depth is produced by the creatures themselves. Also, no shell-phone service. The Titanic lies at 3800m deep.

Between 4000m and 6000m is The Abyss, or Abyssopelagic Zone. With water temperature a little above freezing, and absolutely no light, very few creatures can be found here. About three quarters of the ocean floor is found at this depth. But if you whale-y want to get further away from your anemones, we can go lower.

And so we reach the unforgiving Hadalpelagic zone, extending from 6000m to essentially the very very very very bottom. The deep trenches are found here, and it’s inhabited by a handful of invertebrates like starfish and tube worms. The temperature hovers around freezing and the water pressure is an enormous eight tons per square inch, which is kind of like having the weight of four cars pushing on an area the size of a stamp. Really hard to imagine but its, like, a lot.

So how do scientists measure the depth of the ocean? Well, most estimates are calculated using satellite measurements, which actually look at the seas surface and how it is changed by underlying mountains. This doesn’t give the most accurate picture of the ocean, but this clam be fine tuned with new technologies like high-resolution seafloor mapping done on the NOAA Ship Okeanos Explorer. So far, only about 10% of the sea floor has been mapped to this high accuracy. But, technology is making waves, and soon enough we will be able to see more of the amazing things that our big blue backyard holds…

Like this:

Or this:

Happy nightmares!

 

http://marinebio.org/marinebio/facts/

http://www.seasky.org/deep-sea/ocean-layers.html

http://geology.com/records/deepest-part-of-the-ocean.shtml

http://ocean.si.edu/

http://oceanexplorer.noaa.gov/facts/ocean-depth.html