Physical Features of Asia

Tradition separates Asia and Europe by an arbitrary line beginning in the Arctic Sea and following the Ural Mountains, the Ural River, the Caspian Sea, and the Greater Caucasus. From there it continues along a series of natural breaks, through the Black Sea, the Bosporus, the Sea of Marmara, and the Dardanelles to the Aegean and Mediterranean seas. 

The separation of Asia and Africa is also partly arbitrary. While human beings have provided cleavage by means of the Suez Canal, nature has provided the Red Sea passage to the Indian Ocean. Otherwise, Asia is rather naturally bounded by the Arctic Ocean on the north, the Pacific Ocean on the east, and the Indian Ocean on the south. On the southeast, however, the boundary between Indonesia and the islands of Melanesia is unclear, and scientists have therefore established lines demarcating flora and fauna (for example, Wallace's and Weber's lines)

 

It must not be assumed, however, that this vast and complex region is unified physically, ethnically, or culturally. In fact, diversity is among the few unassailable generalizations that can be stated about Asia.

Certain key geographical features offer clues to human history and presence in Asia. Basic are the implications of comparative size and of position (latitude and longitude), both of which strongly influence the patterns of weather and climate and, in turn, those of soils and vegetation. Perhaps of equal importance is the general arrangement of landforms, especially the highlands that shield some areas from moisture-laden winds yet leave others exposed, producing the drainage systems that have become vital to human development. People naturally tended to congregate where their livelihood was simplest in relation to their technological development.

Relief

A relief diagram of Asia shows a complex mountain system with a core centered on the Pamir plateau northwest of the Indian subcontinent. Stretching eastward across Eurasia from the Atlantic to the Pacific in a series of parallel arcs, the mountains are punctuated by knots, especially in the west. Asia is said to be unique among the continents in having a mountainous heart.

 

Flanking these heights on the north are the world's broadest flatlands, consisting either of virtually featureless plains, as in the west, or of higher land toward the east. Portions of this area, such as Mongolia and Tibet, are partly or entirely enclosed by giant mountain arms radiating from the Pamir. Outlying areas to the southwest, south, southeast, and east often defy these generalizations, being either archipelagic with unique qualities or simply ramifications of the features of the interior.

 

Human beings have naturally preferred level land for settlement. Nevertheless, although much of Asia is level, drought and cold seriously limit vast areas, especially in the interior, as potential habitats. The inhospitableness of a large part of Asia is due mainly to the nature of the landforms and their arrangement and to the pattern of prevailing winds and pressures. Unlike the highlands of North America, those of Asia extend from east to west, blocking most of the interior from the beneficent influence of the warm offshore waters to the south and east. These waters do moderate the climates of the lands situated between the mountains and the sea.

Permanent settlement is therefore found mostly in the flatter parts of this peripheral Asian crescent, from Iraq through the Indian subcontinent to the Sino-Japanese domain, but rarely far from the rivers and seas. The interior behind the mountain barrier has been left to sparse occupancy, usually by nomadic or seminomadic peoples. Notwithstanding some remarkable adaptation, especially by the Russians, the inhabitants of this area have failed to match the agricultural productivity and consequent population growth of the peripheral civilizations.