Asia, the largest of the great divisions of the earth; length, from the extreme south-western point of Arabia, at the Strait of Bab-el-Mandeb, to the extreme north-eastern point of Siberia—East Cape, or Cape Vostochni, in Behring's Strait—6900 miles; breadth, from Cape Chelyuskin, in Northern Siberia, to Cape Romania, the southern extremity of the Malay Peninsula, 5300 miles; area estimated at 17,250,000 sq. miles, about a third of all the land of the earth's surface. On three sides, N., E., and S., the ocean forms its natural boundary, while in the W. the frontier is marked mainly by the Ural Mountains, the Ural River, Caspian Sea, the Caucasus, the Black Sea, the Mediterranean, the Suez Canal, and the Red Sea. There is no proper separation between Asia and Europe, the latter being really a great peninsula of the former. Asia, though not so irregular in shape as Europe, is broken in the S. by three great peninsulas, Arabia, Hindustan, and Farther India, while the east coast presents peninsular projections and islands, forming a series of sheltered seas and bays, the principal peninsulas being Kamtshatka and Corea. The principal islands are those forming the Malay or Asiatic Archipelago, which stretch round in a wide curve on the S.E. of the continent. Besides the larger islands—Sumatra, Java, Borneo, Celebes, Mindanao, and Luzon (in the Philippine group)—there are countless smaller islands grouped round these. Other islands are Ceylon, in the S. of India; the Japanese Islands and Sakhalin on the E. of the continent; Formosa, S.E. of China; Cyprus, S. of Asia Minor; and New Siberia and Wrangell, in the Arctic Ocean.
The mountain systems of Asia are of great extent, and their culminating points are the highest in the world. The greatest of all is the Himálaya system, which lies mainly between long. 70° and 100° E. and lat. 28° and 37° N. It extends, roughly speaking, from north-west to south-east, its total length being about 1500 miles, forming the northern barrier of Hindustan. The loftiest summits are Mount Everest, 29,002 feet high, Godwin-Austen, 28,265, and Kanchinjinga, 28,156. The principal passes, which rise to the height of 18,000 to 20,000 feet, are the highest in the world. A second great mountain system of Central Asia, connected with the north-western extremity of the Himálaya system by the elevated region of Pamir (about long. 70°-75° E., lat. 37°-40° N.), is the Thian-Shan system, which runs north-eastward for a distance of 1200 miles. In this direction the Altai, Sayan, and other ranges continue the line of elevations to the north-eastern coast. A north-western continuation of the Himálaya is the Hindu Kush, and farther westward a connection may be traced between the Himálaya mass and the Elburz range (18,460) feet, south of the Caspian, and thence to the mountains of Kurdistan, Armenia, and Asia Minor.
There are vast plateaux and elevated valley regions connected with the great central mountain systems, but large portions of the continent are low and flat. Tibet forms the most elevated table-land in Asia, its mean height being estimated at 15,000 feet. On its south is the Himálayan range, while the Kuen-Lun range forms its northern barrier. Another great but much lower plateau is that which comprises Afghanistan, Baluchistan, and Persia, and which to the north-west joins into the plateau of Asia Minor. The principal plain of Asia is that of Siberia, which extends along the north of the continent and forms an immense alluvial tract sloping to the Arctic Ocean. Vast swamps or peat-mosses called tundras cover large portions of this region. South-west of Siberia, and stretching eastward from the Caspian, is a low-lying tract consisting to a great extent of steppes and deserts, and including in its area the Sea of Aral. In the east of China there is an alluvial plain of some 200,000 sq. miles in extent; in Hindustan are plains extending for 2000 miles along the south slope of the Himálaya; and between Arabia and Persia, watered by the Tigris and Euphrates, is the plain of Mesopotamia or Assyria, one of the richest in the world. Of the deserts of Asia the largest is that of Gobi (long. 90°-120° E., lat. 40°-48° N.), large portions of which are covered with nothing but sand or display a surface of bare rock. An almost continuous desert region may also be traced from the desert of North Africa through Arabia (which is largely occupied by bare
deserts), Persia, and Baluchistan to the Indus.
POLITICAL MAP OF ASIA
Some of the largest rivers of Asia flow northward to the Arctic Ocean—the Obi, the Yenisei, and the Lena. The Hoang-Ho and Yang-tse, and the Amoor, are the chief of those which flow into the Pacific. The Ganges, Brahmaputra, Irawadi, and Indus flow into the Indian Ocean. The Persian Gulf receives the united waters of the Euphrates and the Tigris. There are several systems of inland drainage, large rivers falling into lakes which have no outlet.
The largest lake of Asia (partly also European) is the Caspian Sea, which receives the Kur from the Caucasus (with its tributary the Aras from Armenia), and the Sefid Rud and other streams from Persia (besides the Volga from European Russia, and the Ural, which is partly European, partly Asiatic). The Caspian lies in the centre of a great depression, being 83 feet below the level of the Sea of Azov. East from the Caspian is the Sea of Aral, which, like the Caspian, has no outlet, and is fed by the Rivers Amu-Darya (Oxus) and Syr-Darya. Still farther east, to the north of the Thian-Shan Mountains, and fed by the Ili and other streams, is Lake Balkhash, also without an outlet and very salt. Other lakes having no communication with the ocean are Lob Nor, in the desert of Gobi, receiving the River Tarim, and the Dead Sea, far below the level of the Mediterranean, and fed by the Jordan. The chief fresh-water lake is Lake Baikal, in the south of Siberia, between long. 104° and 110° E., a mountain lake from which the Yenisei draws a portion of its waters.
Geologically speaking, large areas of Asia are of comparatively recent date, the lowlands of Siberia, for instance, being submerged during the tertiary period, if not more recently. Many geologists believe that subsequently to the glacial period there was a great sea in Western Asia, of which the Caspian and Aral Seas are the remains. The desiccation of Central Asia is still going on, as is also probably the upheaval of a great part of the continent. The great mountain chains and elevated plateaux are of ancient origin, however, and in them granite and other crystalline rocks are largely represented. Active volcanoes are only met with in the extreme east (Kamtchatka) and in the Eastern Archipelago. From the remotest times Asia has been celebrated for its mineral wealth. In the Altai and Ural Mountains gold, iron, lead, and platinum are found; in India and other parts rubies, diamonds, and other gems are, or have been, procured; salt in Central Asia; coal in China, India, Central Asia, &c.; petroleum in the districts about the Caspian and in Burmah; bitumen in Syria; while silver, copper, sulphur, &c., are found in various parts.
Every variety of climate may be experienced in Asia, but as a whole it is marked by extremes of heat and cold and by great dryness, this in particular being the case with vast regions in the centre of the continent and distant from the sea. The great lowland region of Siberia has a short but very hot summer, and a long but intensely cold winter, the rivers and their estuaries being fast bound with ice, and at a certain depth the soil is hard frozen all the year round. The northern part of China to the east of Central Asia has a temperate climate with a warm summer, and in the extreme north a severe winter. The districts lying to the south of the central region, comprising the Indian and Indo-Chinese Peninsulas, Southern China, and the adjacent islands, present the characteristic climate and vegetation of the southern temperate and tropical regions modified by the effects of altitude. Some localities in Southern Asia have the heaviest rainfall anywhere known. As the equator is approached the extremes of temperature diminish till at the southern extremity of the continent they are such as may be experienced in any tropical country. Among climatic features are the monsoons of the Indian Ocean and the eastern seas, and the cyclones or typhoons, which are often very destructive.