Indian Ocean - Facts for Kids

Basic Information

The Indian Ocean is the third-largest ocean on our planet, covering about 20% of Earth’s water surface.

The Indian Ocean touches the shores of more than 30 countries, including India, Australia, Madagascar, and South Africa.

The Indian Ocean covers about 70.56 million square kilometers, which makes it almost seven times bigger than the United States!

The Indian Ocean began forming as pieces of the supercontinent Gondwana split apart about 180 million years ago, and it slowly grew as the continents drifted into new positions.

The Indian Ocean’s average depth is about 3,740 meters.

The Indian Ocean got its name because of its location near India, and people have been sailing on it for thousands of years.

The Indian Ocean lies both north and south of the equator, but a big part of it spreads across the Southern Hemisphere as it stretches toward Antarctica!

The Indian Ocean meets three other bodies of water: the Atlantic Ocean, the Pacific Ocean, and the Southern Ocean.

The deepest part of the Indian Ocean is the Java Trench, and it plunges down to about 7,450 meters — that’s like stacking nearly 17 Empire State Buildings on top of each other!

Most of the Indian Ocean’s seafloor is only tens of millions of years old, so it’s younger than the seafloor of some other oceans!

Physical Features

Some people say the Indian Ocean looks a bit like a giant letter “M” on a world map because of the way its coasts curve between Africa, India, Southeast Asia, and Australia!

The Indian Ocean is home to many beautiful islands — like the Maldives (around 1,190 islands), Seychelles (about 115 islands), and Mauritius.

The Mid‑Indian Ridge is a long underwater mountain range on the Indian Ocean floor — it stretches for several thousand kilometers, where new ocean crust is made as Earth’s plates slowly pull apart!

The Great Australian Bight is a massive curved bay along Australia’s southern coast, and most maps show it as part of the Indian Ocean!

The Indian Ocean has fewer deep trenches than the Pacific Ocean, so its seafloor doesn’t have as many deep, long cracks and is generally less rugged than the Pacific’s!

The Ninety East Ridge is an amazing underwater mountain chain that runs almost perfectly along the 90°E line of longitude for over 5,000 kilometers.

he Indian Ocean has hot underwater volcano vents where water can shoot out at about 400 °C — hot enough to melt metal like lead — even though it doesn’t boil deep under all that pressure!

In many parts of the Indian Ocean, the continental shelf is quite narrow, so the ocean gets deep quickly once you go out from the shore — but in some places the shelf is wider and stays shallow for longer!

The Kerguelen Plateau is a huge underwater volcanic plateau in the southern Indian Ocean — it’s about three times as big as Japan!

Natural Life

The Indian Ocean is home to many thousands of different fish species — from tiny reef fish to big fish like whale sharks — making it one of the most fish‑rich parts of the world’s oceans!

Blue whales—the biggest animals ever—travel through the Indian Ocean on their long migrations, and they can grow as long as three school buses!

Coral reefs in the Indian Ocean provide homes for about 25% of all marine species, even though they cover less than 1% of the ocean floor.

The dugong, also called a sea cow, grazes on seagrass meadows in the shallow parts of the Indian Ocean and can live for up to about 70 years!

Mangrove forests along Indian Ocean coasts are like underwater apartment buildings — their roots give homes and protection to countless fish, crabs, and birds!

The Indian Ocean is home to six of the seven sea turtle species in the world — from olive ridleys to giant leatherbacks!

Some parts of the Indian Ocean contain bioluminescent plankton that glow blue at night when disturbed, creating magical-looking waves that light up beaches!

The Maldives, a country of islands in the Indian Ocean, sits on giant coral reef structures that took millions of years to grow and slowly became the beautiful islands we see today!

Giant clams in the Indian Ocean can grow very big — as long as about a tall kid — and can live for about 100 years!

Climate & Weather

The Indian Ocean is affected by monsoons, seasonal wind patterns that bring heavy rains to countries like India for several months each year.

Surface waters in the Indian Ocean near the equator can get very warm — around 30 °C (86 °F) — making the sea feel as warm as a bath in those sunny tropical waters!

The Indian Ocean experiences cyclones — powerful spinning storms with winds that can blow faster than a race car drives!

The northern Indian Ocean has a unique monsoon current that completely reverses direction twice a year because of changing wind patterns.

El Niño weather patterns in the Pacific Ocean can affect the Indian Ocean, causing droughts in some areas and floods in others.

The southern part of the Indian Ocean experiences the Roaring Forties, incredibly strong westerly winds that helped sailing ships travel quickly in the past.

The Indian Ocean Dipole is like a climate seesaw where one side of the Indian Ocean gets warmer and the other side gets cooler, and this change can affect rainfall and weather in nearby lands.

Human Connection

More than 2 billion people live in countries around the Indian Ocean — in fact, about 2.5 to 2.7 billion people call those countries home, which is around one‑third of all people on Earth!

For thousands of years, sailors used the predictable monsoon winds of the Indian Ocean to travel between Africa, Arabia, India, and Southeast Asia.

Ancient Egyptians sailed early boats over 4,000 years ago and used the Red Sea, which connected them to the Indian Ocean region!

About 40 % of the world’s oil that comes from under the sea is produced in the Indian Ocean region! That oil helps fuel cars, buses, and planes around the world.

The Spice Route was an ancient trading network across the Indian Ocean where merchants exchanged valuable spices, gold, and other treasures.

The Indian Ocean tsunami of 2004 was one of the deadliest natural disasters in history, which led to the creation of better tsunami warning systems.

Many coastal communities around the Indian Ocean celebrate festivals related to the sea, thanking it for providing food and livelihoods.

Scientific Importance

The Indian Ocean floor contains manganese nodules, strange metal-rich rocks that look like potatoes and took millions of years to form!

The first complete map of the Indian Ocean floor wasn't created until the 1960s, making it one of the last major ocean basins to be fully mapped.

The Perth Canyon, underwater near Australia, is as big as the Grand Canyon but completely hidden beneath the waves of the Indian Ocean.

The Indian Ocean has fewer islands than the Pacific Ocean but more than the Atlantic Ocean.

Coelacanths were long believed to have disappeared with the dinosaurs millions of years ago — but in 1938, scientists were stunned when a real coelacanth was caught alive in the western Indian Ocean!

Some beaches around the Indian Ocean have sand that appears pink because it contains millions of crushed red shells from tiny sea creatures.

The Agulhas Current in the Indian Ocean is one of the fastest ocean currents in the world, moving at speeds up to 7 kilometers (4.3 miles) per hour or even faster!

The saltiest part of the Indian Ocean is the Arabian Sea, where intense evaporation removes water but leaves the salt behind.