Open AccessAsymptotic Structure in Eigenfrequencies of Spheroidal Normal Modes of the Earth
Author(s) -
Anderssen R. S.,
Cleary J. R.,
Dziewonski A. M.
Publication year - 1975
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.1975.tb06207.x
Subject(s) - inner core , mantle (geology) , asymptote , normal mode , structure of the earth , homogeneous , shear (geology) , geophysics , geology , physics , outer core , core–mantle boundary , wavenumber , classical mechanics , geometry , mathematics , statistical physics , optics , vibration , petrology , quantum mechanics
Summary The modes of the spheroidal oscillations n S 1 of the Earth can, for small 1 , be classified according to the body wave modes PKIKP (compressional oscillations in the whole Earth), ( SS )v type depends strongly on upper mantle structure. The inner core was virtually homogeneous in the models analysed, and this was reflected in an absence of perturbations in the asymptote of the J mode. Estimates of the radial travel times of each wave type can be derived from the asymptotic eigenperiods. The radial modes n S o are all of PKIKP type, and the asymptotic structure of observed eigenperiods of these modes is clearly perturbed by the presence of the core discontinuities, thus confirming the existence of the solotone effect analysed theoretically by MNabb et al.