Asia Essay, Research Paper
Asia
Asia is the largest of all the continents and includes within its limits an area of 17,159,995 sq mi, or about 33% of the world’s total land surface and the greater part of the Eurasian land mass. The border between Europe is traditionally drawn as an imaginary zigzag line passing down the spine of the Ural Mountains and through the Caspian Sea, Caucasus Mountains, and Black Sea. The boundary dividing Asia and Africa is generally placed along the Suez Canal, and the boundary between Asia and Australasia is usually placed between the island of New Guinea and Australia.
Asia is by far the most populous of all the continents, with an estimated population in 1992 of 3,275,200,000, or more than 60% of the world’s total population. The population is, however, diverse and divided by language, race, religion, politics, economics, and cultural origins into a complex cultural mosaic.
The nations of Asia are usually grouped into five main geographical and political-cultural subdivisions:
1. Southwest Asia, which includes Afghanistan, Armenia, Azerbaijan, Bahrain, Cyprus, Georgia, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, and Yemen, plus Asian Turkey and Egypt east of the Suez Canal (Sinai Peninsula).
2. South Asia, which includes Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka (formerly Ceylon).
3. East Asia, which includes most of the People’s Republic of China, Japan, North Korea (Democratic People’s Republic of Korea), South Korea (Republic of Korea), and Taiwan (Republic of China).
4. Southeast Asia, which includes Brunei, Burma (Myanmar), Indonesia, Kampuchea (Cambodia), Laos, Malaysia, the Philippines, Singapore, Thailand, and Vietnam.
5. Central and North Asia, which includes Kazakhstan, Kyrgyzstan, Mongolia, Tajikistan, Turkmenistan, and Uzbekistan, plus Asian Russia (Siberia) and three of the five autonomous regions of China (Inner Mongolia, Sinkiang-Uighur, Tibet)
LAND AND RESOURCES
Topography
The topography of Asia comprises of a series of high mountain belts, which are the dominant land forms, and a related complex of plateaus, basins, island arcs, and alluvial lowlands. The highest point is Mount Everest, which towers to 29,028 ft in Nepal; the lowest point is 1,296 ft below sea level along the shores of the Dead Sea in Israel and Jordan. The Ural Mountains on the western edge of Asia trend in a north-south direction, but most other belts extend across the continent in a general west-east direction and converge in a knot of high mountains in the Pamirs, located where the borders of Kyrgyzstan, Tajikistan, China, and Afghanistan come together. West of the Pamirs, two main mountain belts are discernible. The southern one crosses the island of Cyprus, enters the mainland to form the Taurus Mountains along the southern edge of Turkey, swings along the southern edge of the Iranian Plateau to form the Zagros Mountains, and on into Pakistan before turning north to become the Hindu Kush and join the Pamirs. The northern mountain belt in Asia west of the Pamirs enters the continent at the Crimean Peninsula, swings eastward to form the Caucasus Mountains between the Black and Caspian seas, continues south of the Caspian Sea as the Elburz Mountains of Iran and the Kopet Mountains on the Iran-Azerbaijan border, and crosses into Afghanistan to merge with the Hindu Kush and the Pamirs.
East of the Pamirs, three mountain belts are discernible. One belt trends northeastward toward the Pacific Ocean and forms the Alai Range in Kyrgyzstan, the Tian Shan (Tien Shan) and Da Hinggan (Greater Khinghan) Range in China, the Altai Mountains in Kazakhstan, and the Sayan, Yablonovy, and Stanovoi mountains in Russia. A second mountain belt, located farther south, extends eastward from the Pamirs to form the Kunlun Mountains, Astin Tagh, and Nan Shan in China. This belt continues across the middle of China, separating North China from South China, as the Qin Ling (Tsinling).
The third and most southerly of the mountain belts radiating eastward from the Pamirs turns southeastward to form the Karakoram Range and the Himalayas and then abruptly southward at the eastern end of the Tibetan Plateau, where it splits into lesser ranges that continue southward as the Arakan Yoma in Burma, the mountainous rib of the Malay Peninsula, and the Annam Mountains (Annamitic Cordillera) in Vietnam.
Numerous plateaus and structural basins are located within or along the margins of these mountain ranges. The highest is the Tibetan Plateau, which has an average elevation of over13,000 ft and is bordered by some of the world’s highest mountains, including the Himalayas on the south, the Karakoram on the west, and the Kunlun Mountains on the north. This entire complex of high mountains and plateaus is often referred to as the “roof of the world.” To the north of Tibet are three important Chinese basins: the Qaidam (Tsaidam) Basin, the Tarim Basin , and the Junggar (Dzungarian) Basin.
Also important to China are the Sichuan (Szechwan, or Red) Basin, located in the western province of Sichuan; the Gobi Plateau, a vast, semidesert upland located in Mongolia and China’s Inner Mongolian Autonomous Region and the Loess Plateau, located south of the Gobi, which is covered with an immense thickness of windblown loess deposits derived from the Gobi. Other plateaus in Asia are the Anatolian Plateau, in Turkey; the Arabian Plateau, mainly in Saudi Arabia; the Deccan Plateau, in peninsular India; and the Vitim and Aldan plateaus, in Russia.
Numerous islands, arranged in a series of arcs, fringe the Southeast Asian and Pacific coasts of the continent. The islands of the Southeast Asian archipelago pick up the main trend lines of Burma’s Arakan Yoma and continue them through the Andaman and Nicobar islands of India and the islands of Sumatra, Java, and Bali in the Indonesian archipelago. Near Bali the main trend of the mountainous belt splits into two segments. One segment continues eastward through the islands of Timor, the Moluccas, and New Guinea and eventually forms the mountains of New Zealand; the other segment turns northeastward and passes in a series of arcs through Borneo, the Philippine archipelago, Taiwan, the Ryukyu Islands, Japan, and Sakhalin and the Kuril Islands before touching the mainland in the Kamchatka Peninsula (Russia). These island arcs are seismically active, and earthquakes and volcanic eruptions frequently occur.
Asia’s most extensive lowlands are located in former Soviet Asia. They are the Western Siberian Plain, a vast, subarctic forested region located east of the Urals, and the Kirghiz Steppe, a semiarid plain located mainly in Kazakhstan. Other important lowlands are mainly in the alluvial valleys and deltas developed by rivers flowing to the south and east. The largest of the alluvial valleys is the Indo-Gangetic Plain, located in the Indian subcontinent between the Himalayas and the Deccan Plateau. Occupying parts of Pakistan, India, and Bangladesh, it is drained by the Indus, Ganges, and Brahmaputra rivers; river water is diverted extensively across the plain for irrigation, and the region is one of the world’s most intensively cultivated and most densely populated places. Other Asian lowlands are the North China Plain, its soils enriched for centuries by loess sediments spread over the valley and deltas of the Huang He (Hwang Ho, or Yellow River); the alluvial valleys and deltas of the Yangtze (China), Irrawaddy (Burma), and Mekong (Cambodia) rivers; and the Fertile Crescent of the Tigris and Euphrates rivers in Iraq.
Geology
Five Asian “shield” areas (geologically stable areas of ancient crystalline rock) are usually recognized. They are the Arabian and Indian shields in the south and the Tarim Basin (Seridian massif), Northern China (the Chinese massif), and the Siberian (Angara) Shield. Great thicknesses of sediments accumulated between these blocks of stable rocks and were subsequently folded and uplifted in periods of mountain building (orogenies). Asia has had a complex orogenic (mountain-building) history. The Caldonian Orogeny occurred in the Silurian and Devonian periods and is recorded in Asia by the Sayan and other mountains of eastern Siberia. The Hercynian Orogeny occurred in the Late Carboniferous (Pennsylvanian) and Permian periods and created several mountain ranges–the Urals, Tian Shan, Kunlun, and Qin Ling (Tsingling).
According to plate-tectonics theory, by the close of the Permian Period, Asia, together with the ancestral cores of all the other continents, formed the supercontinent known as Pangaea. During the Triassic Period, Pangaea split apart into the northern land mass of Laurasia (from which North America, Europe, and northern Asia later developed) and the southern land mass of Gondwanaland (from which India and the continents of the Southern Hemisphere later developed). A large sea called Tethys separated the two landmasses. By the end of the Jurassic Period, Gondwanaland fragmented, and the Indian plate began a northeastward movement. It eventually collided with and was drawn under the edge of the Eurasian plate, and in the process Tethyan sediments were deformed and uplifted to form the Himalayas, Tibetan Plateau, and other high mountains of southern Asia. The African plate moved northward and collided with Eurasia to thrust up the European Alps and the mountains of Asia west of the Himalayas. Much later, probably during the Miocene Epoch, rifting and seafloor spreading created the Red Sea and the Gulf of Aden, and Arabia split away from Africa to form a separate plate. Earth movements occur today in the Indonesian, Japanese, Philippine, and other Pacific island arcs; in these areas there is widespread seismic and volcanic activity, attesting to the geological instability of the region.
Climate
Three broad climatic realms may be distinguished in Asia. They are: monsoon Asia, dry Asia, and cold Asia.
1. Monsoon Asia
The climate of South, Southeast, and East Asia is strongly influenced by the immensity of the Asian land mass, the barrier presented by its great highland core, and the monsoon wind system. In summer, the continental interior of Asia heats up rapidly as a result of increased isolation as the overhead sun moves toward the Tropic of Cancer. Warm air above the heart of Asia rises and creates low-pressure centers. The air pressures above the Pacific and Indian oceans are relatively high. Consequently, strong, moisture-laden winds are drawn inland from the oceans into the low-pressure areas of Asia, bringing heavy rainfall wherever they are forced to rise up over low hills, mountains, or other topographic obstacles. The summer monsoon in India interrupts a very hot, dry spell. Elsewhere in Southeast and East Asia the break is not as dramatic, but rainfall in all of monsoon Asia is concentrated in the summer months. In the coastal region of East Asia, tropical cyclones (typhoons) bring additional precipitation and devastating winds.
In winter, the land surface in the interior of Asia cools off more rapidly than the surrounding oceans. As a result, cold descending air currents over the heart of Asia generate high-pressure centers facing the relatively low-pressure zones over the Indian and Pacific oceans, where temperatures are higher. From October to about April, cold, dry, continental winds blow offshore from inland Asia. This is the season of the winter monsoon.
Places exposed to the monsoons are warmer in summer and colder in winter than places in corresponding latitudes not under their influence. They are also, for the most part, the wettest parts of Asia.
Within this large monsoon area, important temperature differences exist between north and south. An equatorial climate predominates over much of Indonesia and Malaysia; average annual temperature is about 70 degrees F and average annual rainfall more than 80 in. North of the equatorial region is a tropical monsoon area, in which summers are hot and humid (average temperatures over 80 degrees F) and winters cool (50 degrees F) and dry. Rainfall is more than 50 in). Climates in the rest of monsoon Asia range from warm temperate in central China and southern Japan to cool temperate in northern China and Japan. Similarly, the length of the growing season, which is the period between killing frosts in the warm half of the year, decreases gradually from almost a full year in Indonesia to about four months in China’s northeast.
2. Dry Asia
Parts of Southeast Asia, Central Asia, and Mongolia have a wide range of dry climates that range latitudinally from the tropical deserts of the Arabian Peninsula in the west to the subtropical steppe climate present in Iran and Afghanistan and the mid latitude steppe and deserts of Mongolia and northern China. Rainfall varies from a low of less than 1 in in parts of the Gobi Desert to 8 in in Central Asia. Throughout this belt, rainfall is extremely unpredictable. The eastern coastal fringe of the Mediterranean Basin (the Levant) has a typical Mediterranean climate and receives rain in winter; average annual precipitation along this Western edge of dry Asia is about 20 in.
3. Cold Asia
Most of Asian Russia has a cold climate. The southern regions have a subarctic climate, where summers are mild (70 degrees F) and short, lasting for less than four months. Rainfall decreases from about 20 inches in coastal locations to less than 10 in in the interior. The extreme northern section of Asia is dominated by the polar tundra climate, where the low year-round temperatures (warmest month averages below 50 degrees F) create a permanently frozen subsoil known as permafrost.
Drainage
The major rivers of Asia, that is, those reaching the sea, include the Ob, Yenisei, and Lena, which flow northward to the Arctic Ocean; the Amur, Huang He, and Yangtze (the world’s third-longest river, after the Nile and the Amazon), which drain eastward to the Sea of Okhotsk, Yellow Sea, and East China Sea, respectively, all coastal seas of the Pacific Ocean; the Ganges, Indus, and Brahmaputra rivers, which flow southward toward the Indian Ocean; the Mekong, Irrawaddy, and Salween, which rise in eastern Tibet and drain southward through the peninsulas of Southeast Asia; and the Tigris and Euphrates system, which flows into the Persian Gulf, an arm of the Indian Ocean. In addition, about 5,000,000 sq mi of land in Central Asia are drained by rivers that do not reach the sea. This is the internal, or inland, drainage area of Asia. The Ili flows into Lake Balkhash; the Syr Darya and the Amu Darya into the Aral Sea; and the Ural River into the Caspian Sea. Others are intermittent streams, which flow only after heavy rains; their waters evaporate in the deserts, and some end in salt lakes or playas, which may be dry part of the year.
The Dead Sea, a saltwater lake whose shore is the lowest point on Earth, is fed by the Jordan River. The Caspian Sea, also saline and the world’s largest inland body of water, loses more water by evaporation than it receives from streams and precipitation. The Aral Sea, about175 mi to the east, is also saline and once covered a much larger area. Lake Baikal in southern Siberia is the world’s deepest lake (5,712 ft) and has only one outlet, the Angara River. The waters of Lake Baikal are fresh.
Soils
Soil types correspond closely to their respective climatic and natural vegetation regions. In the permafrost region of northern Asia are tundra soils, unusable for agriculture because of the short growing season and impeded drainage but otherwise rich in organic matter. South of the tundra, in the vast coniferous forest region of cold temperate Asia, are podzols with high acidity and low organic content. Farther south, in the zone of mixed coniferous and deciduous forests, the gray brown forest soils have higher humus content and are less acidic than the podzols. Between the temperate forests of northern Asia and the deserts of Central Asia a belt of chernozem and chestnut soils appears. These black to dark-brown soils are very rich in humus and mineral nutrients and are very productive when farmed. The desert and mountain soils of dry Asia have little to offer for agricultural production. Even where irrigation is possible, a danger of salt and alkali accumulation in the topsoil exists resulting from the evaporation of mineralized underground water through capillary action. Consequently, cultivation in dry Asia is confined to well-drained alluvial soils along major river valleys.
The soils of hot, humid monsoon Asia belong to the major soil category known as pedalfers. These soils are rich in iron and aluminum material. High temperatures promote rapid oxidation and contribute to their reddish or yellowish appearance. Heavy rainfall washes soluble mineral and organic matter from the topsoil to the subsoil, leaving insoluble minerals, such as aluminum, in the topsoil. These tropical red earths are generally infertile, and therefore agriculture in monsoon Asia is confined mostly to alluvial soils along river valleys. Some prominent exceptions exist: soils developed on basic volcanic ash in the northeastern Deccan Plateau (India) and in Java are among the richest soils in monsoon Asia.
Vegetation
Much of the original green cover in monsoon Asia has been replaced by secondary growth or farmlands as a result of centuries of cultivation. Even in the equatorial region of Southeast Asia periodic burning by shifting cultivators has greatly reduced the extent of tropical rain forest, and tropical deciduous forests dominate what little forest area remains. These forests yield valuable tropical hardwoods, such as teak, sal, ironwood, and bamboo.