The quick answer to this question is no, the Earth is not made up of 97% water. This is a common myth and misconception about the amount of water on Earth. While water covers around 71% of the Earth’s surface, water only makes up a small percentage of the total mass and volume of the planet.
What percentage of Earth is water?
While often quoted as being around 70-75%, the actual percentage of Earth’s total volume that is water is only about 0.05%. The vast majority of our planet is made up of rocks and other solid matter.
Here is a breakdown of the composition of Earth:
- Crust: 0.5%
- Mantle: 68.1%
- Outer core: 30.8%
- Inner core: 0.4%
- Hydrosphere (water): 0.05%
- Atmosphere: 0.00005%
As you can see, the hydrosphere or all water on Earth makes up less than 1% of the planet’s total volume. The percentage is even smaller if you only consider liquid surface water and freshwater sources.
Where does the 97% myth come from?
The idea that the Earth is 97% water likely comes from a misunderstanding or exaggeration of the fact that about 97% of the world’s water is found in the oceans. Here is a breakdown of all the water on Earth:
- Oceans hold about 96.5% of all water on Earth
- Polar ice caps and glaciers hold about 2%
- Groundwater holds about 1.7%
- Surface water lakes, rivers, etc hold about 0.01%
- Atmosphere holds about 0.001%
So while the oceans contain the vast majority of the planet’s water, the oceans themselves only comprise about 0.05% of the total mass and volume of the Earth.
Where does the 71% surface water statistic come from?
The statistic that about 71% of the Earth’s surface is covered in water comes from the fact that over 70% of the planet’s topography is ocean. But it’s important to note the distinction that this is 71% of the surface area, not the planet’s total volume or composition.
Here is a breakdown of the surface area of Earth that is water versus land:
| Surface Type | Percentage |
|---|---|
| Water (Hydrosphere) | 71% |
| Land (Continents) | 29% |
While the oceans cover a vast area, they are relatively shallow compared to land topography. The average ocean depth is about 2.5 miles compared to the average continental elevation of 2,000 feet above sea level. So the oceans make up a large surface area percentage but contribute a relatively small amount to total planetary volume and mass.
Conclusion
In summary, the statement that the Earth is 97% water is false. The total hydrosphere makes up about 0.05% of the Earth’s total volume. The myth likely comes from the fact that 97% of the water on Earth is found in the oceans themselves, but the oceans are a tiny fraction of the planet’s total composition.
Understanding the breakdown of the composition of the Earth and distinguishing between surface area and total volume percentages is key to debunking the common myth that our planet is almost entirely composed of water. In reality, the Earth is dominated by its rocky, dense interior with only a thin layer of water coating its surface.
While water covers about 71% of the planet’s surface, it only makes up a tiny fraction of the Earth’s total mass and volume. The vast majority of the planet is made up of molten and solid rock and metal.
Knowing the true distribution of water on Earth is important for understanding many geological, ecological, and climatological processes on our unique blue planet.
FAQs
How much water is on Earth?
Earth has about 1.386 billion cubic kilometers of water in total. About 96.5% of this is found in the oceans, while most of the rest is frozen in ice caps and glaciers (2%). Only a tiny fraction (0.05% of total volume) is freshwater sources like rivers, lakes, and groundwater.
Where is most of Earth’s water located?
About 96.5% of all water on Earth is found in the oceans. The vast majority is in the Pacific Ocean (50.1% of all water) and Atlantic Ocean (23.6%). The remaining ocean water is divided between the Indian Ocean, Southern Ocean, and Arctic Ocean.
Is most of the planet water or land?
About 71% of the surface of the Earth is covered in water, mostly consisting of five major oceans. The remaining 29% of the planet’s surface is land consisting of seven continents and many islands.
How much of the Earth’s surface is water vs land?
Approximately 71% of the Earth’s surface is water, while about 29% is land. This consists of:
- Water: 361 million km2
- Land: 149 million km2
Why do people think the Earth is 97% water?
The myth likely originates from the fact that around 97% of the total water on Earth is found in the oceans. But the oceans themselves only comprise about 0.05% of the planet’s total volume and mass. People confuse the percentage of water in the oceans versus the percentage of the Earth that is water.
How was the 97% myth proven false?
Scientists have long known from geophysical research that the interior layers of the Earth are primarily molten and solid rock. Direct measurements demonstrate that water only comprises 0.05% of the planet’s total volume. Seismic waves, gravity, and mineral studies all show that the Earth’s mass is overwhelmingly non-water material.
Where is the remaining water on Earth found?
After the oceans, the remaining water on Earth is found frozen in polar ice caps and glaciers (2%), groundwater (1.7%), surface freshwater sources like lakes and rivers (0.01%), and in the atmosphere (0.001%). The rest exists as soil moisture, water vapor, and in living creatures.
Water Distribution on Earth
The distribution of water on Earth is not even across different reservoirs. Here is how Earth’s total water is divided:
| Reservoir | Volume (km3) | Percent of Total |
|---|---|---|
| Oceans | 1,338,000,000 | 96.54% |
| Ice caps, glaciers | 24,064,000 | 1.74% |
| Groundwater | 23,400,000 | 1.69% |
| Fresh | 20,000 | 0.0015% |
| Saline | 97,000 | 0.007% |
| Soil Moisture | 16,500 | 0.001% |
| Atmosphere | 12,900 | 0.001% |
| Rivers | 2,120 | 0.0002% |
| Lakes | 176,400 | 0.013% |
| Total | 1,386,000,000 | 100% |
As the table shows, the oceans contain the vast majority of Earth’s water, with most of the remainder trapped in ice and underground. Only a tiny fraction exists in readily accessible surface freshwater. This demonstrates how little of the planet’s total water volume is actually available for human use.
Conclusion
While the oceans cover about 71% of the planet’s surface area, the total hydrosphere makes up just 0.05% of the Earth’s total mass and volume. The oft-cited statistic that the Earth is 97% water is not accurate.
This myth likely originates from the fact that 97% of the water on Earth is found in the oceans themselves. But the oceans comprise a tiny fraction of the Earth’s total composition, which is overwhelmingly rocks and other solid matter.
Understanding the true breakdown of the composition of the Earth, versus covering surface area, is key to debunking this common myth. Knowing the actual abundance and distribution of water on our planet provides insight into many important processes that impact our world.
