ice Solid form of liquid water and water vapour. Below 32 °F (0 °C), liquid water forms a hard solid and water vapour forms frost on surfaces and snowflakes (see snow) in clouds. Unlike most liquids, water expands on freezing, so ice is less dense than liquid water and therefore floats. It consists of compact aggregates of many crystals (with hexagonal sym¬ metry), although ice formed from the bulk liquid does not normally have crystal faces. Molecules in the crystal are held together by hydrogen bonds (see hydrogen bonding). With a very high dielectric constant, ice conducts electricity much better than most nonmetallic crystals. At very high pres¬ sures, at least five other crystal forms of ice occur.
ice age or glacial age Any geologic period during which thick ice sheets cover vast areas of land. Such periods of large-scale glaciation may last several million years and drastically reshape surface features of entire continents. A number of major ice ages have occurred throughout the Earth’s history; the most recent periods were during the Pleistocene Epoch (1.8 million-10,000 years ago).
ice cream Frozen dairy food. Ice cream is made from cream or butter- fat, milk, sugar, and flavourings. Fruit ices (nondairy frozen desserts) were introduced into Europe from the East sometime after being first described by Marco Polo in his journals. Creation of the first true cream ice is cred¬ ited to a Parisian cafe owner named Tortoni in the late 18th century. The ice-cream cone originated at the 1904 World’s Fair in St. Louis, Mo., U.S. Commercial ice cream is made by heating and blending its ingredients to form a mix, which is then pasteurized and homogenized. The mix is rip¬ ened for several hours and then agitated while being frozen to incorpo¬ rate air; the highest-quality ice creams incorporate the least air. Ice cream is now available in hundreds, if not thousands, of flavours.
ice dancing Sport in which ice-skating pairs perform to music routines similar to ballroom dances. Ice dancers are judged on the difficulty and originality of their dance steps, their interpretation of the music, and their
French ice dancers Isabelle and Paul Duchesnay competing at the World Ice-Dance Championships.
© DUOMO PHOTOGRAPHY
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924 I ice formation ► Icelandic language
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timing and unison. Unlike figure skating, ice dancing does not allow movements of strength or technical skill (particularly overhead lifts, jumps, and spins of more than one- and-a-half rotations). It has been an Olympic event since 1976.
ice formation Any mass of ice that occurs on the Earth’s continents or surface waters. Such masses form wherever substantial amounts of liq¬ uid water freeze and remain in the solid state for some period of time.
Examples include glaciers, icebergs, sea ice, and ground ice associated With PERMAFROST.
ice hockey Game played on an ice rink by two teams of six players on skates. The object is to drive a puck (a small, hard rubber disk) into the opponents’ goal with a hockey stick, thus scoring one point. A game con¬ sists of three 20-minute periods. The first true ice-hockey game was played in 1875 between two student teams at Montreal’s McGill Univer¬ sity. The National Hockey League, consisting of U.S. and Canadian pro- fessional teams, was organized in
Hockey was introduced at the Olympic Games in 1920. It is a very aggressive game, and the puck is often taken from a player by means of a hit to the body, called a check. Some contact, such as checking from behind and slashing with the stick, is illegal and draws a penalty. See also Stanley Cup.
iceberg Floating mass of ice that has broken from the seaward end of a glacier or a polar ice sheet. Icebergs are typically found in open seas, especially around Greenland and Antarctica. They form mostly during each hemisphere’s spring and summer, when warmer weather increases the rate of calving (separation) of icebergs at the boundaries of the Green¬ land and Antarctic ice sheets and smaller outlying glaciers. In the North¬ ern Hemisphere, about 10,000 icebergs are produced each year from the Greenland glaciers, and an average of 375 flow into the North Atlantic shipping lanes, where they are a hazard to navigation, especially because only about 10% of an iceberg is exposed above the surface of the sea.
Iceland officially Republic of Iceland Island country, northern Atlantic Ocean, between Norway and Greenland. Area: 39,741 sq mi (102,928 sq km). Population (2005 est.): 295,000. Capitaclass="underline" Reykjavik. The people are overwhelmingly Nordic. Language: Icelandic (official). Reli¬ gion: Christianity (Evangelical Lutheran [official]). Currency: krona. One of the most active volcanic regions in the world, Iceland contains about 200 volcanoes and accounts for one-third of Earth’s total lava flow. One- tenth of the area is covered by cooled lava beds and glaciers, including Vatnajokull. Iceland’s rugged coastline is more than 3,000 mi (4,800 km) long. The economy is based heavily on fishing and fish products but also includes hydropower production, livestock, and aluminum processing. Iceland is a republic with one legislative house; its chief of state is the president, and the head of government is the prime minister. Iceland was settled by Norwegian seafarers in the 9th century and was Christianized by 1000. Its legislature, the Althingi, founded in 930, is one of the oldest legislative assemblies in the world. Iceland united with Norway in 1262 and with Denmark in 1380. It became an independent state of Denmark in 1918, but it severed those ties to become an independent republic in 1944. Vigdis Finnbogadottir, the first woman in the world to be elected a head of state, served four terms as the republic’s president (1980-96). See map opposite.
Icelanders' sagas or family sagas Class of heroic prose narra¬ tives written in the 13th century about the great families who lived in Iceland from 930 to 1030. They represent the zenith of classical Icelan¬ dic SAGA writing and are far in advance of any contemporary medieval literature in their realism, controlled style, character delineation, and over¬ whelming tragic dignity. Their artistic unity, length, and complexity sug¬
face-off
goal goal
A typical professional North American ice-hockey rink. U.S. college rinks are usually wider (100 ft), and international rinks vary in both length and width. Blue lines mark the respective off-sides areas; the space between them is called the neutral zone. The puck is put into play by being dropped between two players at the face-off spots; all players except those facing off must stand outside the face-off circle. A major penalty requires that a player go to the penalty box for five minutes while his team plays shorthanded.
gest that they were written by individual authors rather than composed orally. Jus¬ tice, not courage, is often the primary vir¬ tue, as in the greatest of the family sagas,
Njals saga.
Icelandic language National language of Iceland, one of the Ger¬ manic languages. It developed from the Norse speech brought to Iceland by settlers from western Norway in the 9th-10th centuries. Old Icelandic (see Old Norse) is the language of the sagas and other medieval poems. In grammar, vocabulary, and spelling, modern Icelandic is the most con¬ servative of the Scandinavian languages; modern Icelanders can still read Old Norse sagas. Icelandic once borrowed words from Danish, Latin, and the Celtic and Romance languages, but a purist movement that began in the early 19th century has replaced most of these loanwords with words formed only from Icelandic elements.
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Iceman ► identity of indiscernibles I 925