The Handy Geography Answer Book. Paul A Tucci

Sierra Nevada Mountains is 2,425 feet (739 meters) high.

      What is the difference between a sea and an ocean?

      While a sea can be any body of saltwater, it usually refers to a body of saltwater partially or completely enclosed by land. Oceans, though they can also be referred to as seas, are large areas of saltwater, unobstructed by continents.

      How salty is seawater?

      About 3.5% of the weight of seawater is salt (not just sodium chloride or table salt, but also potassium chloride, calcium chloride, and other types of salts). This would equal just over three and one-third cups of salt in one gallon of seawater.

      What are ocean currents?

      The oceans don’t remain still; their water is constantly moving in giant circles known as currents. In the Northern Hemisphere, currents move clockwise, while in the Southern Hemisphere, they move counterclockwise. Currents help to moderate temperatures on land in such northern places as the British Isles, which are farther north than the United States/Canadian border, by sending warm water from the Caribbean northeast across the Atlantic Ocean to northern Europe. A current known as the Antarctic Circumpolar Current circles the southern continent. The North Atlantic and North Pacific oceans each have a large clockwise current, while the South Atlantic and South Pacific oceans each have a large counterclockwise current.

       How tall is the tallest waterfall in the United States?

      Yosemite Falls in California, which is comprised of three separate falls, has a height of 2,425 feet (739 meters).

      What are the largest seas?

      Parts of oceans that are surrounded by islands or otherwise partially enclosed are often known as seas. The five largest seas in order are: the South China Sea, the Caribbean Sea, the Mediterranean, the Bering Sea, and the Gulf of Mexico.

      Why is the Mediterranean Sea so salty?

      Due to the high temperatures in the Mediterranean region, evaporation of the Mediterranean Sea occurs more rapidly than in other bodies of water; therefore, more salt is left behind. The warm, dense, salty water in the Mediterranean is replaced by less salty and dense Atlantic water in the western part of the sea at the Strait of Gibraltar. Water that flows into the Mediterranean from the Atlantic Ocean usually remains in the sea for anywhere from 80 to 100 years before returning to the Atlantic Ocean.

      Has the Mediterranean Sea always been there?

      Salt and sediment found at the bottom of the Mediterranean Sea prove that on several occasions the Mediterranean Sea has dried up, leaving a large layer of salt behind. Scientists speculate that the Strait of Gibraltar has, on occasion, closed up, keeping water from being able to flow back and forth between the Atlantic Ocean and the Mediterranean Sea.

      Where are the four colored seas: Black, Yellow, Red, and White?

      The four colored seas are not geographically associated with one another. The Black Sea is located near the Balkan Peninsula and is bordered by Turkey, Russia, and Ukraine (it is also the home of the port city of Odessa). The Red Sea is located to the south of the Black Sea, between the Arabian Peninsula (Saudi Arabia) and Africa. The Red Sea has been a major trade route for hundreds of years and has been especially useful since the completion of the Suez Canal. The White Sea is in northern Europe. It is part of the Arctic Ocean and is a Russian sea (it lies to the east of Finland). The Yellow Sea is far to the east, between China and the Korean Peninsula.

      What are the seven seas?

      The “seven seas” spoken of by mariners from long ago are oceans or parts of oceans. The Atlantic and Pacific oceans are so large that they were each divided into two “seas.” The Antarctic, Indian, and Arctic were also considered seas, thus totaling seven. If a sailor had sailed upon all seven seas, he had sailed around the world. There are not just seven but dozens of seas in the world.

      Is the Black Sea really black?

      No, it is not. This sea, located to the north of Turkey, is quite deep and has darker-looking water than most water bodies, but receives its name from the severity of the waters when sailing.

      Where is the Putrid Sea?

      The Putrid Sea, also known as the Syvash Sea or Rotten Sea, lies to the east of the Isthmus of Perekop, between Crimea and Ukraine. It is a swampy area of salty lagoons that lie along the west coast of the Sea of Azov and cover an area of approximately 990 square miles (2,560 square km).

RIVERS AND LAKES

      What is the longest river in the world?

      Egypt’s famous Nile River is the longest in the world. It is more than 4,100 miles (6,597 km) long from its sources in the Ethiopian Highlands (the source of the portion of the Nile called the Blue Nile) and Lake Victoria (the source of the White Nile). The Nile Valley is the center of contemporary and ancient Egyptian civilization. Following the Nile in length are the Amazon (in Brazil), the Missouri-Mississippi (United States), the Chang or Yangtze (China), the Huang He or Yellow (China), and the Ob (Russia).

       Do rivers always flow from north to south?

      No, they do not! Rivers always flow from higher ground to lower ground. Though we are familiar with rivers like the Mississippi River in the United States, which flows from north to south, rivers always flow the way gravity takes them. There are many major rivers in Europe, Asia, and North America that flow from south to north, such as the Ob in Russia, the Nile in Africa, and the Mackenzie in Canada.

      The Nile River meanders through much of the eastern part of Africa and is a source of water for seven countries.

      Why are the Blue Nile and White Nile rivers both called Niles?

      The Nile River begins as two separate tributaries—the White Nile and the Blue Nile. The White Nile begins its flow from Lake Victoria in Eastern Africa, and the Blue Nile originates in the Ethiopian Highlands. The Blue Nile and the White Nile converge in Khartoum, the capital of the Sudan, and form the Nile River, which continues on to the Mediterranean. It is approximately 4,258 miles (6,853 km) long.

      Was the flooding of the Nile predictable before dams were built?

      The summer floods of the Nile River were so predictable that the Egyptian calendar was based on their rise and fall. Flooding on the Nile occurred from late June until late October. The floods brought nutrients and sediments beneficial to the nearby agricultural lands, making farming productive throughout the remainder of the year. Measuring scales called “nilometers” were placed along the river and not only measured the river height but also served as calendars. When Egypt’s Aswan Dam was completed in 1970, flooding on the lower stretches of the Nile ceased, but it still occurs in parts of the Sudan.

      What is the longest river in the United States?

      The Missouri-Mississippi River is the longest in the United States, approximately 3,860 miles (6,211 km) in length.

      Where are the highest rivers in the world?

      The highest rivers are in Tibet, where there are two that stand out from all the rest: the Ating River at 20,013 feet (6,100 meters) and the Brahmaputra River at 19,751 feet (6,020 meters).

      Why are the Missouri and Mississippi rivers lumped together?

      Actually, the Missouri River was incorrectly named. The Missouri River is the main feeder river of what is now known as the Mississippi River. Usually, the main feeder bears the same name as the rest of the river. Therefore, the full length of the Mississippi River, including the Missouri River, is known as the Missouri-Mississippi River.

      Which river carries the most water?

      By far, Brazil’s Amazon River carries more water to the sea than any other river in the world. The discharge at the mouth of the river is about seven million cubic feet (170,000 cubic meters) per