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Question of the Day
Question
How much water is there on the earth?
Answer
There's a whole lot of water on Earth! Something like 326,000,000,000,000,000,000 gallons (326 million trillion gallons) of the stuff (roughly 1,260,000,000,000,000,000,000 liters) can be found on our planet. This water is in a constant cycle where it evaporates from the ocean, travels through the air, rains down on the land and then flows back to the ocean.
The reason there is so much water is because the oceans are huge. About 70% of the planet is covered in ocean, and the average depth of the ocean is several thousand feet (about 1,000 meters). 98% of the water on the planet is in the oceans of the world, and therefore is unusable for drinking because of the salt. About 2% of the planet's water is fresh, but 1.6% of the planet's water is locked up in the polar ice caps and glaciers. Another 0.36% is found underground in aquifers and wells. Only about 0.036% of the planet's total water supply is found in lakes and rivers! That's still thousands of trillions of gallons, but it's a very small amount compared to all the water available.
The rest of the water on the planet is either floating in the air as clouds and water vapor, or is locked up in plants and animals (your body is 65% water, so if you weigh 100 pounds, 65 pounds of you is water!). There's also all the soda pop, milk and orange juice you see at the store and in your refrigerator… There's probably several billion gallons of water sitting on a shelf at any one time!
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