Open AccessA Theory of Toroidal Core Oscillations of the Earth
Author(s) -
Shen PoYu
Publication year - 1976
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1976.tb04160.x
Subject(s) - toroid , inner core , physics , compressibility , classical mechanics , concentric , outer core , ellipsoid , mechanics , rigidity (electromagnetism) , rotation (mathematics) , core (optical fiber) , bounded function , elasticity (physics) , geometry , mathematical analysis , mathematics , geophysics , quantum mechanics , optics , thermodynamics , astronomy , plasma
A rotating incompressible fluid bounded by two concentric spherical rigid surfaces can exhibit purely toroidal free oscillations. The eigenfrequencies are fractions of the angular frequency of rotation. If the bounding surfaces are slightly ellipsoidal, secondary spheroidal fields become existent, and in general, a free mode splits into a doublet with one of which exists only when the inner bounding surface is present. For the real earth, the compressibility of the outer core, the elasticity of the solid earth, and the self‐gravitation of the entire earth modify the toroidal core oscillations. The present treatment gives explicitly the effects of these parameters on the eigenfrequencies.