INNER-CORE ANISOTROPY DUE TO THE MAGNETIC-FIELD-INDUCED PREFERRED ORIENTATION OF IRON

被引：110

作者：

KARATO, S

机构：

[1] Department of Geology and Geophysics, University of Minnesota, Minneapolis

来源：

SCIENCE | 1993年 / 262卷 / 5140期

关键词：

D O I：

10.1126/science.262.5140.1708

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Anisotropy of the inner core of the Earth is proposed to result from the lattice preferred orientation of anisotropic iron crystals during their solidification in the presence of a magnetic field. The resultant seismic anisotropy is related to the geometry of the magnetic field in the core. This hypothesis implies that the observed anisotropy (fast velocity along the rotation axis) indicates a strong toroidal field in the core, which supports a strong field model for the geodynamo if the inner core is made of hexagonal close-packed iron.

引用

页码：1708 / 1711

页数：4

共 42 条

[1] THE EARTHS CORE AND THE PHASE-DIAGRAM OF IRON [J].

ANDERSON, OL .

PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 1982, 306 (1492) :21-35

[2] MELTING RELATIONS OF IRON, AND TEMPERATURES IN EARTHS CORE [J].

BIRCH, F .

GEOPHYSICAL JOURNAL OF THE ROYAL ASTRONOMICAL SOCIETY, 1972, 29 (04) :373-&

[3] TEMPERATURES IN THE EARTHS CORE FROM MELTING-POINT MEASUREMENTS OF IRON AT HIGH STATIC PRESSURES [J].

BOEHLER, R .

NATURE, 1993, 363 (6429) :534-536

[4] PHASE-TRANSITIONS, GRUNEISEN-PARAMETER, AND ELASTICITY FOR SHOCKED IRON BETWEEN 77-GPA AND 400-GPA [J].

BROWN, JM ;

MCQUEEN, RG .

JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS, 1986, 91 (B7) :7485-7494

[5] EFFECT OF PRESSURE ON PHYSICS AND CHEMISTRY OF POTASSIUM [J].

BUKOWINSKI, MST .

GEOPHYSICAL RESEARCH LETTERS, 1976, 3 (08) :491-494

[6] HETEROGENEOUS NUCLEATION IN SOLIDIFYING ALLOYS [J].

CANTOR, B ;

DOHERTY, RD .

ACTA METALLURGICA, 1979, 27 (01) :33-46

[7]

Chalmers B., 1964, PRINCIPLES SOLIDIFIC

[8]

Chandrasekhar S., 1967, HYDRODYNAMIC HYDROMA

[9] MAGNETIC SUSCEPTIBILITY AND LOW-TEMPERATURE SPECIFIC HEAT OF HIGH-PURITY TITANIUM [J].

COLLINGS, EW ;

HO, JC .

PHYSICAL REVIEW B, 1970, 2 (02) :235-&

[10] ANISOTROPY OF THE INNER CORE FROM DIFFERENTIAL TRAVEL-TIMES OF THE PHASES PKP AND PKIKP [J].

CREAGER, KC .

NATURE, 1992, 356 (6367) :309-314

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