Transcript PPT - Hss-1.us

Env Sci Week 6 - Geology, Earth and
the Lithosphere
• Major Topographical Featues
The Seven Continents
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(1) Europe: Although referred to as a continent, Europe is actually just the western fifth of the Eurasian landmass,
which is made up primarily of Asia. Modern geographers generally describe the Ural Mountains, the Ural River,
part of the Caspian Sea, and the Caucasus Mountains as forming the main boundary between Europe and Asia.
The second smallest continent (Australia is the smallest), but it has the third largest population of all the
continents, 729 million in 2004. The northernmost point of the European mainland is Cape Nordkinn, in Norway;
the southernmost, Punta de Tarifa, in southern Spain near Gibraltar. From west to east the mainland ranges from
Cabo da Roca, in Portugal, to the northeastern slopes of the Urals, in Russia. The highest point of the continent is
El’brus (5,642 m/18,510 ft), in the Caucasus Mountains in southwestern Russia. The lowest point of Europe is
located along the northern shore of the Caspian Sea, 28 m (92 ft) below sea level.
(2) Asia: Asia, is the largest of the Earth’s seven continents, lying almost entirely in the Northern Hemisphere. Its
peoples account for three-fifths of the world’s population; in 2004 Asia had an estimated 3.86 billion inhabitants.
The lowest and highest points on the Earth’s surface are in Asia, namely, the shore of the Dead Sea (408 m/1,340
ft below sea level in 1996) and Mount Everest (8,850 m/29,035 ft above sea level).
(3) Africa: Africa is the second largest of Earth’s seven continents, covering 23 percent of the world’s total land
area and containing 13 percent of the world’s population. Africa straddles the equator and most of its area lies
within the tropics. It is bounded by the Atlantic Ocean on the west, the Indian Ocean and Red Sea on the east, and
the Mediterranean Sea on the north. In the northeastern corner of the continent, Africa is connected with Asia by
the Sinai Peninsula.
(4) Australia: Australia smallest and is called the island continent located southeast of Asia.
(5) North America: North America is the third largest of the seven continents, including Canada (the 2nd largest
country in area in the world), the United States (3rd largest), and Mexico (14th largest). The continent also
includes Greenland, the largest island
(6) South America: South America is the fourth largest of the Earth's seven continents The lowest point in South
America (40 m/ 131 ft below sea level) is on Península Valdés in eastern Argentina, and the greatest elevation
(6,960 m/22,834 ft) is atop Aconcagua in western Argentina, the highest peak in the Western Hemisphere.
(7) Antarctica: Antarctica is the fifth largest of the Earth’s seven continents. The southernmost, coldest, windiest,
highest, most remote, and most recently discovered continent, it surrounds the South Pole, the point at the
southern end of the Earth’s axis. Almost completely covered by ice.
The Seven Continents
Major Mountain Ranges
• (1) Europe: Pyrenees and Alps
• (2) Asia: Caucus and Pamirs (Parmir hub), Tien Shan
and Himalayas (Mt Everest)
• (3) Africa: the Atlas
• (4) North America: Appalachian Mountains, Alaska
Range, Coastal Ranges, Sierra Nevada and Sierra
Madre
• (5) South America: the Andes
• (6) Australia: the Great Dividing Range
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(7) Antarctica:- Transantarctic Mountains, the West
Antarctica Ranges, and the East Antarctica Ranges.
Major Mountain Ranges
What effects have mountains had on climate and the
development of civilization?
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- Impact of Mountains: Mountains come in many forms. They can be very tall such as the Alps or small hills. They
can be long chains of mountains or they can be isolated. But all have an impact on our environment.
-- The have mineral, forest, agricultural, and recreational resource value
-- They exert a significant influence on climate We will find that they are critical to creating the various climates
around the world. Especially high mountain ranges, such as the Sierra Nevada in the U.S., the Andes in South
America, and the Himalayas in Asia, markedly affect climate and weather patterns over vast areas of the earth
because they stand as barriers to regularly circulating air masses. Moisture carried inland by winds from the
Pacific Ocean, for example, is lost in the form of rain and snow on the windward sides of the Sierra Nevada and
Andes; the leeward, or inland, side is drier, and the land beyond is frequently arid.
-- Mountains that are orientated north to south like the Rocky mountains block the normally westerly flow of the
middle latitudes.
-- E - W oriented mountains such as the Himalayas and the Alps tend to block cold northerly flow in the Northern
hemisphere.
-- The have a great impact on economics and historical trends.
- Example of the Historical Impact of Mountains: The significance of mountains has been very important
throughout history. Similar to oceans, mountain barriers are natural political boundaries. Both the Appalachian and
Rocky mountains have had a great influence upon the development of the United States. The first explorers and
settlers avoided mountains because of the dangers and costs involved. Later, vast deposits of minerals were
found principally in mountainous areas, and the lure of “striking it rich” drew people and railroads west despite the
hardships encountered in traversing the passes. As a result, transportation routes and pattern and associated
large populations centered developed in the mountain areas, and most of these remain today.
Other Major Topographical
Features
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Beside mountains there are other significant features of the earth including islands, plains and
deserts.
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In geology, the term island is used to describe an area of land completely surrounded by water
when the land is too small to be called a continent.
(1) Ocean islands are the tops of the mountains, may have been formed from volcanoes.
(2) Island arcs form on an anticline fold that reaches the surface of the ocean.
(3) Micronesia which means "small islands" is a nation that is composed of many small islands.
These tropical islands are situated 5,150 km west-southwest of Honolulu in the North Pacific
Ocean, and about three-quarters of the way between Hawaii and Indonesia. Micronesia is spread
over 3 million square miles of the Pacific and includes over 2000 islands. The distance from one
end of Micronesia to the other is 2,040 nautical miles.
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28.1. Islands
28.2. Plains and Deserts
(1) Plains: Plains are regions of generally level (flat) or gently rolling terrain. Plains are good for
agriculture and easy transportation. A good example is the Great Plains of the United States.
(2) Deserts: Deserts cover about one fifth of the Earth’s surface and occur where rainfall is less
than 50 cm (20 inches) per year. Deserts are technically not a landform, but they typically are
located to the leeward (opposite side of the usual wind direction) of large mountain ranges.
Most deserts, such as the Sahara of North Africa and the deserts of the southwestern U.S.,
Mexico, and Australia, occur at low latitudes (closer to the Equator than the Poles). But another
kind of desert, cold deserts, occurs in the basin and range area of Utah and Nevada and in parts
of western Asia. Most deserts have a considerable amount of specialized vegetation, as well as
specialized animals. Soils often have abundant nutrients. They need only water to become very
productive and have little or no organic matter.
Topography of the U.S
• The US can be divided up into the following 10 geological or
topographical regions:
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(1) Southwest Coastal - California
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(2) Northwest Coastal - Oregon - Washington
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(3) Rocky Mountains
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(4) Southwest Desert
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(5) Great Plains
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(6) Midwest Prairie
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(7) Gulf States
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(8) Appalachian Mountain
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(9) East Coast
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(10) Great Lakes Region
Topography of New York
• New York state can be divided up into the
following 7 geological or topographical regions:
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(1) Adirondacks
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(2) Lake Ontario - Lake Plains (includes
finger lakes) and St Lawrence River Valley
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(3) Tug Hill Plateau
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(4) Hudson and Mohawk Valleys
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(5) Coastal Plain and Long Island
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(6) Southern Tier - Allegheny Plateau
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(7) Lake Erie - Western NY