The Ocean Floor

Anything which looks like this is a link to the next page!

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What do you think of when you imagine the ocean floor?

Talk this over with your partner for a minute.

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You probably think of

something likethis…

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…and maybe you imagine underwater life like this…

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…but did you ever think the ocean looks like this?

It does!

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As the ocean gets deeper, it also gets darker.

Sunlight only penetrates about 500 ft.

down to 20,000 ft

0- 500 ft

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As the ocean becomes deeper and darker, it

also becomes…

Colder Hotter

Try again!

Yes! The ocean varies greatly in temperature, all the way from the

tropical waters (100 degrees F) near the equator to the freezing waters (0

degrees F) of the North and South poles.

Warmer waters

Colder waters

Life in tropical waters is very similar to life in the rainforest. There is a lot of variety; which means there are many different kinds of species. The temperature of the water is close to that

of your bath tub at home.

This is the Great Barrier Reef, off of the coast of Australia. As you can see, there is a lot of life here! Coral reefs support about 25% of all marine (underwater) life in the ocean.

This is a kelp forest. They are common in temperate (moderate, or medium)

temperatures off the coast of California and parts of South America. They are very

productive ecosystems!

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Life in the cold waters of the Arctic and Antarctic is very different from the life in the tropics. Because the water is so cold, many animals have adapted, and developed their own ways keeping

warm. Plants are very scarce!

A certain type of fish, called nototheniods, have developed a natural antifreeze in their blood. This helps them withstand very cold temperatures.

Mammals in cold water, such as this Beluga whale, have many layers of blubber, or fat, to

keep themselves warm.

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Now that we have some background information, we can begin with the parts of the ocean floor.

Continental Edge

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Continental Shelf

This is the part of the continental crust which is underwater. It can vary from almost nothing to 930 miles wide! Remember when we looked at Google Earth? The continental shelf was the light blue part off the coast, and it is the same in this picture.

The shelf has the most sunlight out of any layer of the ocean, because it is only 0-600 ft deep. This means many animals and plants

thrive (do very well) here.

Do you think the continental shelf has...

90% of all marine life

or only 35% of all marine life?

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The continental shelf is very shallow, which means sunlight can get into the water. This allows photosynthesis, a process which plants

use to get food. This means many animals also thrive.

Oops! Try again!

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That’s right!

The shelf has the most sunlight out of any layer of the ocean, because it is only 0-600 ft deep. This means many animals and plants thrive here; 90% of all marine life to be exact! Included are the coral reefs and kelp forests we talked about earlier. When you

swim in the beach, you are in the continental shelf.

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Continental EdgeNext is the continental edge. This is an easy one!

It is the point at which the continental shelf turns into the continental slope! The ocean floor starts to become much

steeper. In this picture, look at the black line (it is an ongoing point). Next

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The continental slope is a very steep drop beginning at the continental edge. It extends to over two miles deep. The water

becomes much colder and the pressure increases greatly.

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Continental RiseThis is the last part of the gradual slope before the ocean floor.

Much like the continental shelf, edge, and slope, it is covered in mud, sand, and rocks. They layers of the continental rise are very thick

because sediments are deposited here.

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Click on the arrows next to the landforms to learn more about

them.After you have finished all 4, click

next.

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Abyssal PlainThe abyssal plain begins at the bottom of the continental rise. It

is mostly flat and there is no light and very little oxygen. This means that there are very few plants and animals. The ground is covered with sand and mud, and the remains of

plants and animals that have sunk to the bottom.

Check out creatures of the deep!

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This eel, called the umbrellamouth gulper, puffs out it’s mouth to catch whatever life it can find.

This fish has a barb which comes out of it’s chin, as well as two rows of glow-in-the-

dark spots running along it’s sides.

This creature, known as the vampire squid, has giant eyes compared to the size of it’s body, which is only about 6 inches long.

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Called the longnose chimaera, this shark-like animal can reach up to 5 ft long! It has an extremely poisonous spine on its back. It can kill a person!

This fish, although only 3 inches long, has its own fish hook and

light attached to its back!

These are called “Prince Axel’s wonderfish,” and how they are indeed! They have their own organ which dangles from their mouth to create light. It helps attract other smaller creatures.

Back to the arrows

Guyots

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Back to the arrows

This is a computer-generated image of a

guyot. They are seamounts (islands

formed by volcanoes) that have been

flattened by waves.

Seamounts

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Back to the arrows

A seamount is an underwater mountain that forms from erupting volcanoes. If a seamount rises above the surface of the water, it is an island. The Hawaiian Islands were formed this way.

Ocean Trenches

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Back to the arrows

A trench in the ocean is very similar to a

canyon (like the Grand Canyon) on land. It is formed by rivers and

currents cutting through the ocean floor. Trenches are extremely deep and

dark. The deepest trench on Earth is almost 7 times

as big as the Grand Canyon!

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