Is inner core seismic anisotropy a marker for plastic flow of cubic iron?
نویسندگان
چکیده
منابع مشابه
The inner inner core of the Earth: Texturing of iron crystals from three-dimensional seismic anisotropy
We present a three-dimensional model of the seismic anisotropy and texturing of iron crystals in the inner core. The form of the anisotropy changes suddenly at slightly less than half of the inner core radius. The outer part is composed of iron crystals of a single phase with different degrees of preferred alignment along the spin axis of the Earth. The inner part may be composed of a different...
متن کاملInner core attenuation anisotropy
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...
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...
متن کاملComplex seismic anisotropy in the top of the Earth’s inner core beneath Africa
[1] We report complex seismic anisotropy in the top 80 km of the Earth’s inner core beneath Africa. The anisotropy in the top 80 km of the inner core is constrained using differential travel times, amplitude ratios, and waveforms of the PKiKP-PKIKP phases sampling Africa along various directions. The differential PKiKP-PKIKP time residuals (relative to the Preliminary Reference Earth Model [PRE...
متن کاملRegional variation of inner core anisotropy from seismic normal mode observations.
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...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Geophysical Research Letters
سال: 2015
ISSN: 0094-8276,1944-8007
DOI: 10.1002/2014gl062862