mantle, portion of the earth's interior lying beneath the crust and above the core. No direct observation of the mantle, or its upper boundary, has been made; its boundaries have been determined solely by abrupt changes in the velocities and character of seismic waves passing through the earth's interior (see seismology). Samples of the upper mantle may be provided by some volcanic eruptions in ocean areas, e.g., the Hawaiian Islands. The continental and ocean crusts, along with part of the solid upper mantle, make up the lithosphere to a depth of about 62 mi (100 km). Within the lithosphere is the Mohorovičić discontinuity, or Moho, considered to be the mantle's upper surface, at depths ranging from 4 to 43 mi (7 to 70 km). Analysis of seismic waves indicates that rocks below the Moho are less rigid and slightly more dense than rocks making up the crust. A zone of low seismic velocity and rigidity just below the lithosphere, called the asthenosphere, is present in the upper part of the mantle, from 62 mi (100 km) to 156 mi (250 km). Its presence is of critical importance to plate tectonics. The mantle continues to the Gutenberg discontinuity at the liquid outer core, with the base of the mantle located about 1,800 mi (2,900 km) below the earth's surface. The entire mantle constitutes about 84% of the earth by volume. Its composition is thought to be similar to peridotite, an igneous rock of mostly magnesium-rich silicate.

Welsbach mantle or Welsbach burner [for C. A. von Welsbach], cylindrical framework of gauze impregnated with oxides of thorium and cerium. When heated in a gas flame, it produces a very bright light because of the incandescence of the oxides. It is now used in outdoor and camp lamps.

Mantle, Mickey (Mickey Charles Mantle), 1931-95, American baseball player, b. Spavinaw, Okla. In 1951, he joined the New York Yankees of the American League; eventually he replaced Joe DiMaggio in center field. A powerful and speedy switch-hitter, Mantle had a total of 536 regular-season home runs, and a lifetime batting average of .298. His 18 home runs in World Series play remains a record. He was voted the league's Most Valuable Player in 1956 (when he won the triple crown, leading the league in batting average, home runs, and runs batted in), in 1957 (when he hit a career-high .365), and in 1962. In 1961 he and teammate Roger Maris both threatened Babe Ruth's single-season record of 60 home runs; Mantle, slowed by an injury, finished with 54, while Maris hit 61. Retiring in 1968, Mantle entered the Baseball Hall of Fame in 1974. His career was hampered by osteomyelitis of his left leg and by various injuries. Another problem, his alcoholism, contributed to his death from liver cancer. In the last months of his life he received a liver transplant, and spurred efforts to increase public awareness of transplant therapy.

in full Mickey Charles Mantle

(born Oct. 20, 1931, Spavinaw, Okla., U.S.—died Aug. 13, 1995, Dallas, Texas) U.S. baseball player. Mantle joined the New York Yankees in 1951 and became a powerful switch-hitting outfielder and first baseman. Between 1954 and 1961 “the Mick” led the American League four times in home runs, six times in runs, and once in RBIs, the latter occurring in the year (1956) that he won the triple crown for home runs, RBI, and batting average (.353). In 1961 he hit 54 home runs, finishing second in the home-run race behind his teammate Roger Maris, who broke Babe Ruth's season record that same year. Mantle had to play with his legs heavily taped for much of his career because of injuries to his ankles and knees. He retired in 1968 with a lifetime total of 536 home runs.

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in full Mickey Charles Mantle

(born Oct. 20, 1931, Spavinaw, Okla., U.S.—died Aug. 13, 1995, Dallas, Texas) U.S. baseball player. Mantle joined the New York Yankees in 1951 and became a powerful switch-hitting outfielder and first baseman. Between 1954 and 1961 “the Mick” led the American League four times in home runs, six times in runs, and once in RBIs, the latter occurring in the year (1956) that he won the triple crown for home runs, RBI, and batting average (.353). In 1961 he hit 54 home runs, finishing second in the home-run race behind his teammate Roger Maris, who broke Babe Ruth's season record that same year. Mantle had to play with his legs heavily taped for much of his career because of injuries to his ankles and knees. He retired in 1968 with a lifetime total of 536 home runs.

Learn more about Mantle, Mickey with a free trial on Britannica.com.