Hemispherical anisotropic patterns of the Earth's inner core
2010 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 107, no 21, 9507-9512 p.Article in journal (Refereed) Published
It has been shown that the Earth's inner core has an axisymmetric anisotropic structure with seismic waves traveling similar to 3% faster along polar paths than along equatorial directions. Hemispherical anisotropic patterns of the solid Earth's core are rather complex, and the commonly used hexagonal-close-packed iron phase might be insufficient to account for seismological observations. We show that the data we collected are in good agreement with the presence of two anisotropically specular east and west core hemispheres. The detected travel-time anomalies can only be disclosed by a lattice-preferred orientation of a body-centered-cubic iron aggregate, having a fraction of their  crystal axes parallel to the Earth's rotation axis. This is compelling evidence for the presence of a body-centered-cubic Fe phase at the top of the Earth's inner core.
Place, publisher, year, edition, pages
2010. Vol. 107, no 21, 9507-9512 p.
elastic anisotropy, Fe-bcc/-hcp, PKiKP/PKIKP waves, molecular dynamics
IdentifiersURN: urn:nbn:se:kth:diva-27563DOI: 10.1073/pnas.1004856107ISI: 000278054700008ScopusID: 2-s2.0-77953107436OAI: oai:DiVA.org:kth-27563DiVA: diva2:378314
QC 201012152010-12-152010-12-132010-12-15Bibliographically approved