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estimated to contain 187 quintillion gallons of water. That quantity is equal to about one-third of the water of all the oceans. The Pacific Ocean is by far the largest body of water on Earth, stretching from the Arctic in the north to Antarctica in the south with a maximum depth of more than 11,000 meters. The Pacific Ocean moves clockwise in the Northern Hemisphere and counter clockwise in the Southern Hemisphere. Its temperatures range anywhere from 29.5 F, which is below the
freezing point of water, all the way up to 86 F near the equator. MORE FROM REFERENCE.COM About 70 percent of the planet is covered in ocean, and the average depth of the ocean is around 12,100 feet. B. Tanaka / Getty Images There's a whole lot of water on Earth! Something like 326,000,000,000,000,000,000 gallons (that's 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 — it evaporates from the ocean, travels through the air, rains down on the land and then flows back to the ocean. The oceans are huge. About 70 percent of the planet is covered in ocean, and the average depth of the ocean is about 12,100 feet (3,688 meters). Ninety-eight percent of the water on the planet is in the oceans, and therefore is unusable for drinking because of the salt. Less than 3 percent of the planet's water is fresh, but about 1.6 percent of the planet's water is locked up in the polar ice caps and glaciers. Another 0.36 percent is found underground in aquifers and wells. Only about 0.036 percent 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 percent water, so if you weigh 100 pounds, 65 pounds of you is water!) With 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! • Water Science School HOME • Water Basics topics • How much water is there on, in, and above the Earth?All Earth's water, liquid fresh water, and water in lakes and rivers Spheres showing:(1) All water (largest sphere over western U.S., 860 miles (1,385 kilometers) in diameter)(2) Fresh liquid water in the ground, lakes, swamps, and rivers (mid-sized sphere over Kentucky, 169.5 miles (272.8 kilometers) in diameter), and (3) Fresh-water lakes and rivers (smallest sphere over Georgia, 34.9 miles i(56.2 kilometers) n diameter).Credit: Howard Perlman, USGS; globe illustration by Jack Cook, Woods Hole Oceanographic Institution (©); and Adam Nieman. The Earth is a watery place. But just how much water exists on, in, and above our planet? About 71 percent of the Earth's surface is water-covered, and the oceans hold about 96.5 percent of all Earth's water. Water also exists in the air as water vapor, in rivers and lakes, in icecaps and glaciers, in the ground as soil moisture and in aquifers, and even in you and your dog. Water is never sitting still. Thanks to the water cycle, our planet's water supply is constantly moving from one place to another and from one form to another. Things would get pretty stale without the water cycle! All Earth's water in a bubbleThe globe illustration shows blue spheres representing relative amounts of Earth's water in comparison to the size of the Earth. Are you surprised that these water spheres look so small? They are only small in relation to the size of the Earth. This image attempts to show three dimensions, so each sphere represents "volume." The volume of the largest sphere, representing all water on, in, and above the Earth, would be about 332,500,000 cubic miles (mi3) (1,386,000,000 cubic kilometers (km3)), and be about 860 miles (about 1,385 kilometers) in diameter. The smaller sphere over Kentucky represents Earth's liquid fresh water in groundwater, swamp water, rivers, and lakes. The volume of this sphere would be about 2,551,000 mi3(10,633,450 km3) and form a sphere about 169.5 miles (272.8 kilometers) in diameter. Yes, all of this water is fresh water, which we all need every day, but much of it is deep in the ground, unavailable to humans. Do you notice the "tiny" bubble over Atlanta, Georgia? That one represents fresh water in all the lakes and rivers on the planet. Most of the water people and life on earth need every day comes from these surface-water sources. The volume of this sphere is about 22,339 mi3 (93,113 km3). The diameter of this sphere is about 34.9 miles (56.2 kilometers). Yes, Lake Michigan looks way bigger than this sphere, but you have to try to imagine a bubble almost 35 miles high—whereas the average depth of Lake Michigan is less than 300 feet (91 meters). Water is on and in the EarthThe vast majority of water on the Earth's surface, over 96 percent, is saline water in the oceans. The freshwater resources, such as water falling from the skies and moving into streams, rivers, lakes, and groundwater, provide people with the water they need every day to live. Water sitting on the surface of the Earth is easy to visualize, and your view of the water cycle might be that rainfall fills up the rivers and lakes. But, the unseen water below our feet is critically important to life, also. How do you account for the flow in rivers after weeks without rain? In fact, how do you account for the water flowing down a driveway on a day when it didn't rain? The answer is that there is more to our water supply than just surface water, there is also plenty of water beneath our feet. Learn more at the Water Science SchoolEven though you may only notice water on the Earth's surface, there is much more freshwater stored in the ground than there is in liquid form on the surface. In fact, some of the water you see flowing in rivers comes from seepage of groundwater into river beds. Water from precipitation continually seeps into the ground to recharge aquifers, while at the same time water in the ground continually recharges rivers through seepage. Humans are happy this happens because we make use of both kinds of water. In the United States in 2010, we used about 275 billion gallons (1,041 billion liters) of surface water per day,and about 79.3 billion gallons (300.2 billion liters) of groundwater per day. Although surface water is used more to supply drinking water and to irrigate crops, groundwater is vital in that it not only helps to keep rivers and lakes full, it also provides water for people in places where visible water is scarce, such as in desert towns of the western United States. Without groundwater, people would be sand-surfing in Palm Springs, California instead of playing golf. How much water is there on (and in) the Earth? Here are some numbers you can think about:
Where is Earth's water located?For a detailed explanation of
where Earth's water is, look at the data table below. Notice how of the world's total water supply of about 332.5 million mi3 of water, over 96 percent is saline. Of total freshwater, over 68 percent is locked up in ice and glaciers. Another 30 percent of freshwater is in the ground. Rivers are the source of most of the fresh surface water people use, but they only constitute about 509 mi3 (2,120 km3), about 1/10,000th of one percent of
total water. One estimate of global water distribution
Source: Igor Shiklomanov's chapter "World fresh water resources" in Peter H. Gleick (editor), 1993, Water in Crisis: A Guide to the World's Fresh Water Resources (Oxford University Press, New York). Sources and more information:
How much gallons of water is in the world?The total amount is estimated to be 326 million cubic miles (326x106 cubic miles). One cubic mile of water equals more than one trillion (1012) gallons or 3.785 trillion liters, making the total amount of water available about 326 quintillion gallons or 1233.91 quintillion liters.
How much total water is in the ocean?According to the U.S. Geological Survey, there are over 332,519,000 cubic miles of water on the planet. A cubic mile is the volume of a cube measuring one mile on each side. Of this vast volume of water, NOAA's National Geophysical Data Center estimates that 321,003,271 cubic miles is in the ocean.
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