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Anshan ► Antarctica I 79
Anshan \'an-,shan\ City and territory of ancient Elam, north of modern Shiraz, Iran. Anshan came to prominence c. 2350 bc, but its greatest period was in the 13th- 12th centuries bc, when, as kings of Anshan and Susa, Elamite rulers periodically raided the cities of Babylonia. The area appar¬ ently came under the control of the Persians c. 675 bc. Its ruins have yielded major finds, including examples of early Elamite writing.
Anshan Van-'shan\ or An-shan City (pop., 1999 est.: 1,285,849), Liao¬ ning province, northeastern China. Established as a post station in 1387, it was fortified in 1587 as part of the defenses set up by the Ming dynasty against the rising power of the Manchus. It was destroyed by fire during the Boxer Rebellion and badly damaged during the Russo-Japanese War (1904-05). In the 1930s the Japanese occupied Anshan and made it a steel¬ making centre. The city was bombed by U.S. aircraft in 1944 and looted by the Soviets following World War II. The Chinese later redeveloped it into an industrial centre that produces steel, cement, and chemicals.
ant Any member of approximately 8,000 species of the social insect family Formicidae. Ants are found worldwide but are especially com¬ mon in hot climates. They range from 0.1 to 1 in. (2-25 mm) long and are usually yellow, brown, red, or black. Ants eat both plant and animal substances; some even “farm” fungi for food, cultivating them in their nests, or “milk” aphids. Ant colonies consist of three castes (queens, males, and workers, including sol¬ diers) interacting in a highly com¬ plex society paralleling that of the honeybees. Well-known ant species America, the voracious army ants of tropical America, and the stinging FIRE ANT.
antacid Any substance, such as sodium bicarbonate, magnesium hydrox¬ ide, or aluminum hydroxide, used to relieve the discomfort caused by indi¬ gestion, gastritis, and several forms of ulcers. Antacids counteract or neutralize gastric acidity for up to three hours after a single dose. Antacids should be taken when gastric acidity is most likely to be increasing— namely, between one and three hours after each meal and at bedtime.
Antakya See Antioch
Antananarivo X.an-ta-.na-na-'re-voV formerly Tananarive \ta-,na-na-'rev\ City (pop., 2001 est.: 1,403,449), capital of Madagascar. Located in central Madagascar Island, and rising to an elevation of 4,694 ft (1,431 m), the city was founded in the 17th century and was controlled by the Merina from the early 1790s until the end of the 19th century. The French made it the capital of their colony when they took control of the region at the end of the 19th century and renamed it Tananarive. The name became Antananarivo after the 1972 revolution. The University of Mada¬ gascar (1961) is located there, as are tobacco- and food-processing plants. A railway connects it with Toamasina, the island’s chief port.
Antarctic Circle Parallel of latitude approximately 66.5° south of the Equator that circumscribes the southern frigid zone. It marks the northern limit of the area within which, for one day or more each year, the sun does not set or rise. The length of continuous day or night increases southward from the Antarctic Circle, mounting to six months at the South Pole.
Antarctic regions Antarctica and the southern portions of the Pacific, Atlantic, and Indian oceans. The waters around Antarctica are sometimes called the Southern Ocean; however, the term “Antarctic Ocean” is some¬ times also used, inappropriately. Much of the area is characterized by subpolar conditions, and ice shelves and sea ice extend well beyond the borders of the continent. Water cooled by the coastal ice masses of the Antarctic continent sinks and flows northward along the ocean bottom and is replaced at the surface by warmer water flowing south from the Indian, Pacific, and Atlantic oceans. The meeting point of these currents is the Antarctic Convergence, an area rich in phytoplankton and krill, which are important to various species of fish as well as to penguins and seabirds.
Antarctica Fifth largest continent on Earth. Antarctica lies concentri¬ cally about the South Pole, its landmass almost wholly covered by a vast ice sheet averaging 6,500 ft (2,000 m) thick. It is divided into two sub¬ continents: East Antarctica, consisting mainly of a high, ice-covered pla¬ teau, and West Antarctica, consisting largely of an archipelago of
Carpenter ant (Camponotus)
GRACE THOMPSON FROM THE NATIONAL AUBUDON SOCIETY COLLECTION-PHOTO RESEARCHERS/EB INC.
are the carpenter ants of North
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2002 Encyclopaedia Britannica, Inc.
mountainous islands covered with ice. Its land area is about 5.5 million sq mi (14.2 million sq km). The southern portions of the Atlantic, Pacific, and Indian oceans surround it (see Antarctic regions). Antarc¬ tica would be circular except for the outflaring Antarctic Peninsula and two principal bays, the Ross Sea and the Weddell Sea. East and West Ant¬ arctica are separated by the long chain (1,900 mi [3,000 km]) of the Tran- santarctic Mountains. The ice sheet overlaying the continent represents about 90% of the world’s glacial ice. By far the coldest continent, it has the world’s lowest recorded temperature, -128.6 °F (-89.2 °C), measured in 1983. The climate supports only a small community of land plants, but the rich offshore food supply sustains penguins and immense seabird rookeries. There are no permanent human inhabitants. The Russian F.G. von Bellingshausen (b. 1778—d. 1852), the Englishman Edward Brans- field (b. 1795?—d. 1852), and the American Nathaniel Palmer (b. 1799—d. 1877) all claimed first sightings of the continent in 1820. The period to c. 1900 was dominated by the exploration of Antarctic and sub- Antarctic seas. The early 20th century, the “heroic era” of Antarctic explo¬ ration, produced expeditions deep into the interior by Robert Falcon Scott and later Ernest Shackleton. The South Pole was reached by Roald Amund¬ sen in December 1911 and by Scott in January 1912. The first half of the 20th century was also Antarctica’s colonial period. Seven nations claimed sectors of the continent, while many other nations carried out explora¬ tions. In the International Geophysical Year of 1957-58, 12 nations estab¬ lished over 50 stations on the continent for cooperative study. In 1961 the Antarctic Treaty, reserving Antarctica for free and nonpolitical scientific study, entered into full force. A 1991 agreement imposed a ban on min¬ eral exploitation for 50 years.
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80 I anteater ► anthracite
anteater Any of four species of toothless, insect-eating placental mam¬ mals. Found in tropical savannas and forests from Mexico to northern Argentina and Uruguay, anteaters have a long tail, dense fur, a long skull, and a tubular muzzle. Their mouth opening is small, and the tongue is long and wormlike. They live alone or in pairs and feed mainly on ants and termites, which they obtain by inserting their sticky tongue into a nest torn open by the long, sharp, curved claws of their forefeet. The species range in length from 15 in. (37 cm) to 6 ft (1.8 m). Once grouped together, anteaters are now considered as separate from echidnas and pangolins.