How Much Do You Know About the Ocean and the Things In It?


By: Heather Cahill

6 Min Quiz

Image: Shutterstock

About This Quiz

Most of the world is covered in ocean, which is why our blue planet is blue. Even though we cannot yet live on this majority of our planet's surface, oceans are the source of human survival. They provide food, they enable rapid transport and transit of goods, and lifeforms contained within them support every ecosystem on the planet. 

Without them, we would have a lot more land, sure, but we wouldn't have a breathable atmosphere, and we'd probably still be exploring the planet's surface since we wouldn't have gotten around very fast.

Access to the shoreline is one of the most significant deciding factors in the success of human civilization. The "Roman pond" of the Mediterranean sustained more great empires than almost any other patch of water by merely giving them easy access to their own territories. 

Meanwhile, New York City became the most significant trading port in North America by virtue of its massive deepwater harbor, which wiggles around so much that it provides a shocking 650 miles of coastline for just the one city.

Despite all this wealth and opportunity, we often don't know what's beneath the surface - but we have begun to explore and bring back a few choice facts. Let's see if you know them!

These are on land and erupt, but they are also underwater. What are they?

There are volcanoes underwater. These volcanoes are called submarine volcanoes and after erupting, the output is vital to marine life's survival in the ocean.


What is the largest ocean in the world?

The largest ocean in the world is the Pacific Ocean. It is larger than all of the land on Earth and covers more than 63 million miles of area. It also touches the Americas and Australia.


Which deep sea creature has teeth so large that it can't close its mouth?

The Pacific Viper Fish has teeth so large that it can't close its mouth. The Pacific Viper Fish lives hundreds of meters below the ocean's surface.


What is the deepest area of the ocean?

The deepest part of the ocean is the Marianas Trench. The trench is over 10,000 meters deep and surprisingly, there are living creatures down in the hole.


What is the largest whale you will find in the ocean?

The Blue Whale is the largest whale found in the ocean. They are also the largest animals in the world. The large animals can be as long as 100 feet.


What is the hottest ocean?

The Indian Ocean is the hottest ocean. The ocean has reached temperatures as high as 86 degrees Fahrenheit. In contrast, the coldest part of an ocean is called the Antarctic Bottom Water found in the Southern Ocean.


How much of the ocean is covered in ice?

Seven percent of the ocean is covered in ice. Most of this ice is located in Antarctica and surprisingly, Greenland. These are cold areas where glaciers can typically thrive.


How long does it take for water to travel around the world?

It takes water 1,000 years to travel around the world. The water travels in a distinct pattern throughout the world, which helps it to make its journey back and around once again.


How much salt is in the ocean?

The salt found in the ocean is 3 percent. This number doesn't sound like a lot, but it really adds up! The salt comes from the erosion of minerals by the water.


How deep can a diver in suit go?

A diver in suit can go 2,000 feet deep into the ocean. Divers consume their oxygen very fast underwater and recreational divers usually have a limit of only 130 feet.


Where is the Mid-Atlantic Mountain Ridge found?

The Mid-Atlantic Mountain Ridge is found in the Atlantic, Pacific and Indian Oceans. The ridge was created by the movement of tectonic plates.


Which underwater plant grows at extreme speeds?

The giant kelp grows at extreme speeds. In one day, it can grow up to two feet! Giant kelp are very important to marine life as many species live in them and eat them.


What produces much of the oxygen that we breathe?

Seaweed produces much of the oxygen that we breathe. Without seaweed, much of the marine life that we know today wouldn't survive. We have these algae to thank for our oxygen and marine life.


How much of the Earth's surface is ocean?

Seventh percent of the Earth's surface is ocean. Most of the ocean has never been explored by humans due to limitations in how far we are able to travel and our technology.


From where does the ocean get its color?

The ocean gets its color from the sun. The beams of blue from the sun are projected across the ocean, which makes it blue. This is also true for the sky.


The male of which marine species gives birth?

The male seahorse gives birth. He is also the one that takes care of the young. He can give birth to up to 2,000 babies and has a very short pregnancy.


What type of whale was Moby Dick?

Moby Dick was a sperm whale. These whales are found in the ocean and they are able to reach depths of more than 3,000 feet. They are also known to eat a lot of fish each day.


Which marine animal has been around for over 500 million years?

Jellyfish have been around for over 500 million years. They are one of the oldest organisms that has ever lived on the planet. They are even older than the dinosaurs!


What is a hypoxic area?

A hypoxic area is an area of pollution under the water that can create lifeless patches throughout the ocean. Human pollution is the cause of some of these areas, but there are natural causes as well.


What valuable item is found in the ocean?

The ocean hides a goldmine beneath its surface. The water is filled with trillions of dollars worth of gold waiting to be mined, although it isn't an easy or effective process.


What does a starfish have on each of its limbs?

Starfish have eyes on each of their limbs. This helps them to see. If they lose their arms, they also have the ability to regrow them, similar to an octopus.


Which of the following are closely related to sea urchins?

Sand dollars are closely related to sea urchins. These are creatures that are truly alive, despite the fact they appear to be beautiful, patterned chunks of sand.


In the Antarctic Ocean, what is unique about the aquatic animals?

In the Antarctic Ocean, animals contain a natural anti-freeze that allows them to live in the frigid waters. The anti-freeze keeps their blood from freezing up.


The world's oldest what has been found under the ocean?

The world's oldest city was found under the ocean. The city is estimated to be more than 9,000 years old and it is located near India. It is under just over 100 feet of water.


Where would you find the largest waterfall?

The largest waterfall is located underwater in between Greenland and Iceland. It is truly the largest waterfall in the world, even though it doesn't look like your typical waterfall!


What weird object is found at the bottom of every ocean?

Manganese balls are found in every ocean. They vary in size and can be found in patches on the bottom of the ocean's floor.


What animal is also known as a "sea hedgehog"?

Sea urchins are also known as "sea hedgehogs." They closely resemble a hedgehog with their small and spiky bodies. The little creatures may seem harmless, but they are able to sting.


Which ocean animal has three hearts?

An octopus has three hearts. In fact, it has multiples of many body parts, including nine brains! These eight-legged creatures can even spray ink.


Which marine animal sleeps with one eye open?

Dolphins sleep with one eye open. They are extremely intelligent and use this trick to keep themselves safe from danger.


How much of the ocean have we explored?

We have currently only explored about 5 percent of the ocean. The ocean is not as easy to explore as land is, but we have been making progress each year. More knowledge is being obtained each day as we explore further and further.


Which marine animal doesn't appear to be alive, but is?

Sea sponges don't appear to be alive, but they are a living species! They have no vitals, but some of these sponges are actually able to move.


Where does the color on coral reefs come from?

The color on coral comes from algae that lives on them. Coral is often thought to be a rock, but it is actually a living species. Coral feeds on fish as well as from the algae.


What color of algae would you find in warm water?

Red algae would be found in warmer water. Green is another color of algae that you would likely find in warm water. These algae are commonly found on corals.


What is the world's largest living structure?

The Great Barrier Reef is the world's largest living structure. It is located off the coast of Australia and it is well known for its beauty and coral.


What is the Zhemchug?

Zhemchug is an underwater canyon found in the Bering Sea. It is both extremely large and deep, and it also can't be seen entirely from the Earth.


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