Does one fifth of the world's water realy flow over Niagra Falls..?

Question

The Readers Digest states,"One fifth of the world's fresh water plunges over Niagra Falls". I find this very hard to believe, considering the Amazon, Mississippi, Columbia. Nile and thousands of others I don't even know the names of. Where would I find the facts??

Answer 1

Today, 20 percent of the world’s fresh surface water is contained in the five great lakes: 5,473 cubic miles (22,812 km³), or 6 quadrillion U.S. gallons (22.81 quadrillion litres) in all. It is enough water to cover the contiguous 48 states to a uniform depth of 9.5 feet (2.9 m). The combined surface area of the lakes is 94,250 square miles (244,100 km²)— larger than the states of New York, New Jersey, Connecticut, Rhode Island, Massachusetts, Vermont and New Hampshire combined.

Niagara Falls is located on the Niagara River, between Lake Erie and Lake Ontario. Since water doesn't flow "uphill" over the falls, then the contents of Lake Ontario cannot be included in the 20 percent figure.

Which means the Reader's Digest statement is incorrect, if only considering the Great Lakes themselves.

However, adding in the additional water flowing into the Lakes from the nearby catchments (via all the rivers that dump into them), then the 20 percent number is ~probably~ correct. Of course, it would take an ENORMOUS length of time for that amount of water to flow over the falls ... the Falls flow rate is 6000000 cubic feet (4.488 x10^7 US Gallons) per minute.

Doing the math: (6 x 10^15) / (4.488 x 10^7) = 133928571. So, in about 134 billion hours (or 15288 years), the 20 percent would cross the lip of the Falls...

Answer 2

You probably misread it, or there was a typo in the Digest, considering that we have the Amazon, the Nile, the Yangtze, Mississippi, Victoria Falls, and Angel Falls, and every other river and waterfall in the world. No way does a fifth of it flow over Niagara.

Answer 3

Niagara Falls is a set of massive waterfalls located on the Niagara River in eastern North America, on the border between the United States and Canada. Niagara Falls (French: les Chutes du Niagara) comprises three separate waterfalls: the Horseshoe Falls (sometimes called the Canadian Falls), the American Falls, and the smaller, adjacent Bridal Veil Falls. While not exceptionally high, Niagara Falls is very wide. With more than 6 million cubic feet (168,000 m³) of water falling over the crestline every minute[1] in high flow, and almost 4 million cubic feet (110,000 m³) on average, it is the most powerful waterfall in North America.

You could get more information from the link below...

Answer 4

It could be possible that 1/5 of the worlds FRESH water flows over niagra falls, but not 1/5 of ALL the worlds water

Answer 5

Not all at once, of course. The basins of the Great Lakes are earth's largest fresh water reservoirs in liquid form. Only the polar ice caps of Antarctica and Greenland contain more fresh water.
One answerer got it right, stating that the Niagara Falls only empty that freshwater body. It probably takes decades or even centuries to replace the entire amount of water stored in the Great Lakes.

Answer 6

One fifth of all the fresh water in the world lies in the four Upper Great Lakes-Michigan, Huron,
Superior and Erie. All the outflow empties into the Niagara river and eventually cascades over
the falls.

Answer 7

That's misleading. If you wait long emough, sure 1/5 of the world's fresh water will pour over Niagara Falls. Without a time scale that statement means nothing.

Answer 8

Suppose you have a mass m kg of water Potential energy = mgh = 490 m Gain in temperature = mc t where c = specific heat capacity of water = 4200 joules/ kg/ c therefore 490 = 4200 t or t = 0.12 C Please note that the water will be landing in a large volume of water which will probably have cooled back to the original temperature and so the actual increase will be much less.

Answer 9

"Reader's Digest" is called a "bathroom reader" for a reason - it should be used for toilet paper.

Niagra Falls is considered the most "powerful" waterfall in North America but certainly not the entire world.

Answer 10

Yes