Lincot A., Merkel S., Cardin Philippe. (2015). Is inner core seismic anisotropy a marker for plastic flow of cubic iron ?. Geophysical Research Letters, 42 (5), p. 1326-1333. ISSN 0094-8276.
Titre du document
Is inner core seismic anisotropy a marker for plastic flow of cubic iron ?
Geophysical Research Letters, 2015,
42 (5), p. 1326-1333 ISSN 0094-8276
This paper investigates whether observations of seismic anisotropy are compatible with a cubic structure of the inner core Fe alloy. We assume that anisotropy is the result of plastic deformation within a large-scale flow induced by preferred growth at the inner core equator. Based on elastic moduli from the literature, body-centered cubic or face-centered cubic Fe produces seismic anisotropy well below seismic observations (<0.4%). A Monte Carlo approach allows us to generalize this result to any form of elastic anisotropy in a cubic system. Within our model, inner core global anisotropy is not compatible with a cubic structure of Fe alloy. Hence, if the inner core material is indeed cubic, large-scale coherent anisotropic structures, incompatible with plastic deformation induced by large-scale flow, must be present.
