Normal-mode splitting due to inner-core anisotropy
نویسندگان
چکیده
منابع مشابه
Robust normal mode constraints on inner-core anisotropy from model space search.
A technique for searching full model space that was applied to measurements of anomalously split normal modes showed a robust pattern of P-wave and S-wave anisotropy in the inner core. The parameter describing P-wave anisotropy changes sign around a radius of 400 kilometers, whereas S-wave anisotropy is small in the upper two-thirds of the inner core and becomes negative at greater depths. Our ...
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We investigate the attenuation structure of the Earth's inner core and its relationship to the velocity structure globally and along various sampling directions, by studying the amplitude ratios and the differential travel times of the PKiKP–PKIKP and PKPbc– PKIKP phases. Our observations reveal that the amplitude ratios of these core phases, like the differential travel times, vary in both sam...
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Earth's solid inner core is surrounded by a convecting liquid outer core, creating the geodynamo driving the planet's magnetic field. Seismic studies using compressional body waves suggest hemispherical variation in the anisotropic structure of the inner core, but are poorly constrained because of limited earthquake and receiver distribution. Here, using normal mode splitting function measureme...
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The spectra of 25 inner-core-sensitive normal modes observed following eight recent major (Mw >7.5) earthquakes are inverted for anisotropic structure in the inner core, using a one-step inversion procedure. The mode data are combined with PKP(DF)^ PKP(AB) di¡erential traveltime data and the inner core is parametrized in terms of general axisymmetric anisotropy, allowing structure beyond restri...
متن کاملInner-core Anisotropy and Rotation
■ Abstract This paper reviews recent research focused on the Earth’s inner core. Large inner-core traveltime anomalies and the anomalous splitting of core-sensitive free oscillations strongly suggest that the inner core is anisotropic. Initial models involved a simple, constant or depth-dependent cylindrical anisotropy at a level less than a few percent. Recent observations suggest that its eas...
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ژورنال
عنوان ژورنال: Geophysical Journal International
سال: 1995
ISSN: 0956-540X,1365-246X
DOI: 10.1111/j.1365-246x.1995.tb06451.x