Archive for February 25, 2012

Erkin | February 25, 2012
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Global water distribution

For an estimated explanation of where Earth’s water exists, look at the chart below. By now, you know that the water cycle describes the movement of Earth’s water, so realize that the chart and table below represent the presence of Earth’s water at a single point in time. If you check back in a thousand or million years, no doubt these numbers will be different!

Notice how of the world’s total water supply of about 332.5 million cubic miles of water, over 96 percent is saline. And, of the total freshwater, over 68 percent is locked up in ice and glaciers. Read more

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Erkin | February 24, 2012
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Water on and in the Earth

Where is Earth’s water located and in what forms does it exist? You can see how water is distributed by viewing these bar charts. The left-side bar shows where the water on Earth exists; about 97 percent of all water is in the oceans. The middle bar shows the distribution of that three percent of all Earth’s water that is freshwater.

Picture of Earth showing if all Earth’s water (liquid, ice, freshwater, saline) was put into a sphere it would be about 860 miles (about 1,385 kilometers) in diameter. Diameter would be about the distance from Salt Lake City, Utah to Topeka, Kansas, USA.

Credit: Illustration by Jack Cook, Woods Hole Oceanographic Institution; USGS.

The majority, about 69 percent, is locked up in glaciers and icecaps, mainly in Greenland and Antarctica. You might be surprised that of the remaining freshwater, almost all of it is below your feet, as ground water. No matter where on Earth you are standing, chances are that, at some depth, the ground below you is saturated with water. Of all the freshwater on Earth, only about 0.3 percent is contained in rivers and lakes—yet rivers and lakes are not only the water we are most familiar with, it is also where most of the water we use in our everyday lives exists. Read more

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Erkin | February 23, 2012
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Thirsty? How ’bout a cool, refreshing cup of seawater?

No, don’t take us literally! Humans cannot drink saline water. But, saline water can be made into freshwater, which everyone needs everyday. The process is called desalination, and it is being used more and more around the world to provide people with needed freshwater.

 

Most of the United States has, or can gain access to, ample supplies of fresh water for drinking purposes. But, fresh water can be in short supply in some parts of the country (and world). And, as the population continues to grow, shortages of fresh water will occur more often, if only in certain locations. In some areas, salt water (from the ocean, for instance) is being turned into freshwater for drinking. Read more

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Erkin | February 17, 2012
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A Human Right to Water

Lack of safe water has significant costs to societies in terms of health costs, lost economic productivity, and human suffering. For example, 14,000 to 30,000 people die each day from water-related diseases; most of these deaths are children and elderly persons. Concerns over these losses and suffering

Access to safe and reliable local water supplies is a major challenge in many communities in developing countries. Without the benefit of piped-in supplies, many people must devote part of their day to securing water for their daily needs. In this photograph, Pakistani villagers pull drinking water from a 122-meter (400-foot) well. Read more

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Erkin | February 16, 2012
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Water Found on Distant Planet

After a few false starts, astronomers say they have finally observed water vapor in the atmosphere of a so-called hot Jupiter, a large gaseous planet tightly orbiting a distant star. Using NASA’s Spitzer Space Telescope, a research team measured the infrared starlight shining through the atmosphere of planet HD 189733 b as it passed in front of its star 63 light-years away.

The planet soaked up infrared light at several wavelengths in a pattern expected of water molecules, as detailed online today in Nature. “This is the first convincing detection of water in the atmosphere of a planet outside our own solar system,” says Heather Knutson, an astronomy graduate student at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., who was not involved in the study. Read more

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