WATERWAYS

About 70% of the Earth’s surface is covered by water.

The amount of water in the world always remains the same. Water moves from place to place; it changes state from solid to liquid to gas and back; it is consumed and discharged; it is dirtied and cleaned. But in the end, there’s only so much water and what there is, simply gets recycled again and again.

The water we drink today may be the same water that a dinosaur ingested millions of years ago or that flowed in the Nile in Cleopatra’s time (and you thought your teacher was OLD)!

This Water Cycle is made up of a few main parts:  Evaporation  Condensation  Precipitation  Collection

70% of the Earth’s surface is covered by water but of all that water, 97% is salty ocean water. Of the remaining 3%, more than 2/3 is frozen in glaciers and polar ice sheets. That leaves less than 1% that is available for human consumption.

Water makes up 79% of our body. It takes less than a 1% deficiency in our body’s water to make us thirsty. A 5% deficit causes a slight fever. An 8% shortage causes the glands to stop producing saliva and the skin to turn blue. A person cannot walk with a 10% deficiency and a 12% deficiency brings death.

 75% of Americans are chronically dehydrated.  The brain is about 75% water and is the first organ affected by dehydration, which causes loss of concentration and memory.  Lack of water is the #1 trigger of drowsiness and headaches.

 1 out of 5 people in the world are without access to safe drinking water.  50% of the world’s population lacks adequate water purification systems.  In developing countries, 90-95% of sewage and 70% of industrial wastes are dumped untreated into waters where they pollute the useable water supply.

 2.2 million people die each year from diseases associated with unsafe drinking water.  50% of all diseases could be controlled easily if people had access to clean drinking water.  33% of all deaths in developing nations are caused by contaminated water.

We do have a limited supply of good, clean fresh water and we need to preserve it.

In 2000, the International Hydrographic Organization created the fifth world ocean - the Southern Ocean, also known as the Antarctic Ocean. It consists of the southern portions of the Atlantic, Indian, and Pacific Oceans (below 60° south latitude). Some geographers disagree on its existence, so the debate will continue.

The largest and deepest ocean in the world is the Pacific Ocean. It covers more than 1/3 of the Earth’s surface and is 18 times the size of the U.S. The Pacific contains more than half the world’s seawater.

The deepest point in any ocean is the Mariana Trench in the Pacific Ocean. The water here is 36,198 feet deep (over 7 miles-Mount Everest is only 6 miles high). It would take a 2½ pound ball of steel dropped into the water above the Mariana Trench nearly 64 minutes to fall to the bottom.

The Atlantic Ocean is the second-largest ocean in the world and is slightly less than 9 times the size of the U.S.

The Indian Ocean covers about 28 million square miles and holds 20% of the world’s water. Most of the Indian Ocean lies in the tropical zone making it the warmest of the four oceans.

Pacific Ocean32-84 degrees Atlantic Ocean degrees Indian Ocean degrees

The Arctic Ocean is the Earth’s smallest ocean (10 times smaller than the Pacific). It surrounds the North Pole and is frozen all the time, except at its edges, making it the coldest ocean.

Why are oceans salty?

The salt comes from the land. Salt is found in soil and rocks and as precipitation falls, it picks up some of the salt and carries it to rivers. Rivers carry it to seas. Since this has been happening for millions of years, the oceans now have a lot of salt (about one cup per gallon)!

When seawater evaporates, the salts do not. They remain in the water and accumulate more and more, year after year. The oceans contain enough salt to build a wall 180 miles high and a mile thick. This wall would reach once around the world at the Equator (25,000 miles).

A sea is a branch of one of the oceans and is partially enclosed by land. The world’s largest sea is the South China Sea. Its region is the world’s second busiest international sea lane.

A strait is a narrow body of water that connects two larger bodies of water.

A lake is a body of water surrounded by land. Most lakes contain fresh water rather than salt water. This is because they have rivers flowing out of them as well as into them. The rivers carry the salt away so it doesn’t collect in the lakes and make their waters salty. If a lake is salty, it is because it has a river that flows into it but none flowing out of it.

Some bodies of water commonly known as “seas” are really lakes. These include the Sea of Galilee and the Dead Sea, which is the lowest (1,302 feet below sea level) and the saltiest lake in the world (8 times saltier than the ocean).

Other lakes that have been misnamed seas are the Aral Sea and the Caspian Sea (the largest lake in the world at 143,243 sq. miles-it is salty).

Don Juan Pond in Antarctica is the saltiest body of water on earth. This shallow pool of water has such a high salt content that it remains a liquid even at temperatures as low as -63 degrees. At its saltiest, the percentage of salt by weight is 40.2%, compared to 23.1% in the Dead Sea and a 3.38% average in the world’s oceans as a whole.

The 5 Great Lakes (Super Man Helps Every One) The largest freshwater lake in the world is Lake Superior (31,700 sq. miles).

The deepest lake in the world is Lake Baikal located in Russia. It’s greatest depth is more than 5,700 feet. More than 300 rivers empty into the lake.

The highest navigable freshwater lake in the world is Lake Titicaca. It sits at 12,507 feet above sea level.

The longest lake in the world is Lake Tanganyika (420 miles).

Lake Nyasa (Lake Malawi) is the most southerly of the great African Rift Valley lakes. It is 365 miles long and 52 miles wide and is often called Calendar Lake.

The world’s longest river is the Nile River in Africa. It is 4,145 miles long.

The Amazon River, the second-longest river at 3,915 miles long, is the world’s widest and most navigable river. At its widest point, it is 7 miles wide during the dry season. During the rainy season, when it floods the surrounding plains, it can be up to 28 miles wide.

The Amazon has over 1,000 tributaries with an average depth of 50 feet. It carries the largest volume of freshwater in the world. The outpouring of water is so great at its mouth (which is 150 miles wide), that for a distance of about 200 miles, the Atlantic Ocean has fresh water.

Most rivers flow from north to south, but not all of them do! The Nile River actually flows from the south to the north. The most important point to remember is that rivers flow from high ground to low ground. They flow toward an ocean, lake, sea, or another river.

The tallest waterfall in the world is Angel Falls found in Venezuela. It has a drop of 3,212 feet and is 20 times higher than Niagara Falls.