Imagine standing on a beach, gazing out at the vast ocean. The waves crash against the shore, and the water stretches endlessly to the horizon. Have you ever wondered just how big the ocean really is?
First, let’s understand that there is actually only one ocean. It’s divided into five main parts: the Pacific, Atlantic, Indian, Arctic, and Southern Oceans. These are often called separate oceans, but they are all connected, forming one gigantic body of water that covers most of our planet.
The ocean covers about 71% of Earth’s surface, which is around 360 million square kilometers. To put that in perspective, it’s more than 36 times the size of the United States! From space, the ocean is the most noticeable feature of our planet. It holds over 1.3 billion cubic kilometers of water. Imagine enough water to cover the entire United States with a layer 132 kilometers deep—that’s how much water is in the ocean!
The ocean contains 97% of all the water on Earth. It also holds 99% of the world’s biosphere, which is the area where life exists. In comparison, the land where we live makes up only 1% of the biosphere. The ocean is crucial for life on Earth.
The ocean is home to some incredible geological features:
This is the world’s longest mountain range, stretching about 65,000 kilometers underwater. It’s ten times longer than the Andes, the longest mountain range on land.
Under the Denmark Strait, there’s a massive underwater waterfall. It carries 116 times more water per second than the Congo River’s Inga Falls, the largest waterfall on land by volume.
The tallest mountain on Earth is actually in the ocean. Mauna Kea in Hawaii rises 4,200 meters above sea level, but its base is 5,800 meters below the ocean’s surface. From top to bottom, it’s about 10,000 meters tall, making it taller than Mount Everest.
This is the deepest canyon in the world, located 11 kilometers below the ocean’s surface. It’s six times deeper than the Grand Canyon and could easily submerge Mount Everest with room to spare.
The ocean is enormous and vital to our planet. It shapes our world and supports countless forms of life. However, it’s not beyond our reach. About 50% of the world’s population lives within 100 kilometers of a coastline, and many others live near water sources that connect to the ocean. This means almost everyone can impact the ocean’s health.
Human activities affect every part of the ocean, no matter how remote. While the ocean defines our planet, we also have the power to define the ocean’s future. Let’s work together to protect this incredible resource.
Using a large sheet of paper or a digital tool, draw a map of the world and label the five main parts of the ocean: Pacific, Atlantic, Indian, Arctic, and Southern Oceans. Include major features like the Mid-Ocean Ridge and the Challenger Deep. This will help you visualize how these parts connect to form one vast ocean.
Using the information that the ocean covers about 71% of Earth’s surface, calculate the approximate area of the ocean in square kilometers. Compare this to the size of different countries or continents to better understand its vastness. Share your findings with the class.
Choose a specific ocean region and research the types of life found there. Create a presentation or poster showcasing the biodiversity of that area. Highlight how this biodiversity contributes to the ocean’s role as the world’s largest biosphere.
Investigate the different depths of the ocean, from the shallow continental shelves to the deep ocean trenches like the Challenger Deep. Create a 3D model or diagram to illustrate these depths and include interesting facts about each zone.
Hold a class discussion on how human activities affect the ocean. Consider both positive and negative impacts. Propose actions that individuals and communities can take to protect the ocean. Document the discussion and create a plan to implement some of these actions locally.
Imagine yourself standing on a beach, looking out over the ocean, waves crashing against the shore, blue as far as your eyes can see. Let it really sink in, the sheer scope and size of it all. Now, ask yourself, “How big is it? How big is the ocean?”
First, we need to understand that there really is only one ocean, consisting of five component basins that we call the Pacific, the Atlantic, the Indian, the Arctic, and the Southern. Each of these five, while generally referred to as oceans in and of themselves, is truly part of a single, massive body of water—one ocean—which defines the very face of planet Earth.
The ocean covers roughly 71% of our planet’s surface, some 360 million square kilometers, an area in excess of the size of 36 USAs. It’s such a vast spread that, when viewed from space, the ocean is, by far, the dominant feature of our planet. The ocean currently holds over 1.3 billion cubic kilometers of water. Put another way, that’s enough water to immerse the entire United States under a body of salt water over 132 kilometers tall—a height well beyond the reach of the highest clouds and extending deep into the upper atmosphere.
With all that volume, the ocean represents 97% of Earth’s total water content. On top of that, the ocean contains upwards of 99% of the world’s biosphere, which is the spaces and places where life exists. The immediate world as we know it, indeed the totality of all the living space encompassed by the continents themselves, represents only 1% of the biosphere—1%! The ocean is everything else.
So, the ocean is physically massive. Its importance to life is practically unparalleled. It also happens to hold the greatest geological features of our planet. Here are four of the most notable:
1. The ocean contains the world’s largest mountain range, the mid-ocean ridge. At roughly 65,000 kilometers long, this underwater range is some 10 times longer than the longest mountain chain found purely on dry land—the Andes.
2. Beneath the Denmark Strait exists the world’s largest waterfall. This massive cataract carries roughly 116 times more water per second over its edge than the Congo River’s Inga Falls, the largest waterfall by volume on land.
3. The world’s tallest mountain is actually found in the ocean, hiding in plain sight. While 4,200 meters of Hawaii’s Mauna Kea sit above sea level, its sides plummet beneath the waves for another 5,800 meters. From its snow-covered top to its silt-covered bottom, this Hawaiian mountain is roughly 10,000 meters in height, dwarfing Everest’s peak by well over a kilometer.
4. The world’s deepest canyon, the Challenger Deep, exists 11 kilometers below the ocean’s surface, some six times deeper than the Grand Canyon. That’s deep enough to sink Mount Everest and still have over 2.1 kilometers of water sitting atop its newly submerged peak.
So, however you choose to slice it, the ocean is BIG! It defines our planet, is home to the greatest geological features, comprises the largest living space, and is home to the greatest numbers and forms of life on Earth. It is practically incomprehensible in scope.
But it is not so big, so vast, so extraordinary as to be untouchable. In fact, with roughly 50% of the world’s population living within 100 kilometers of a coastline, and with most of the remainder living close enough to lakes, rivers, or swamps—all of which ultimately lead to the ocean—virtually every single person on the planet has the opportunity to influence the general health and nature of the world ocean.
Evidence of human influence is seen in every part of the ocean, no matter how deep or distant. The ocean defines our planet, but, in a very real sense, we define the ocean.
Ocean – A large body of saltwater that covers most of Earth’s surface and surrounds its continents. – The Pacific Ocean is the largest and deepest ocean on Earth.
Water – A transparent, tasteless, odorless, and nearly colorless chemical substance that is essential for all known forms of life. – Freshwater from rivers and lakes is crucial for human consumption and agriculture.
Biosphere – The global sum of all ecosystems, including all life forms and their relationships with the environment. – The biosphere is vital for maintaining the balance of gases in the atmosphere.
Planet – A celestial body orbiting a star, large enough to be rounded by its own gravity and to have cleared its orbital path of other debris. – Earth is the only known planet that supports life in the solar system.
Coastline – The outline or shape of the land where it meets the ocean or sea. – Erosion and rising sea levels can significantly alter a coastline over time.
Features – Distinctive attributes or aspects of the Earth’s surface, such as mountains, valleys, and rivers. – The Grand Canyon is one of the most famous natural features in the United States.
Life – The condition that distinguishes living organisms from inorganic matter, including the capacity for growth, reproduction, and continuous change preceding death. – Scientists study fossils to understand how life on Earth has evolved over millions of years.
Coverage – The extent to which something is covered or included, often referring to the area affected by a particular phenomenon. – Satellite images provide coverage of deforestation in the Amazon rainforest.
Activities – Actions or tasks performed by humans or animals that can impact the environment. – Human activities such as mining and agriculture can lead to habitat destruction.
Health – The state of being free from illness or injury, often used to describe the condition of ecosystems and the environment. – The health of coral reefs is threatened by pollution and climate change.
