title: Hemispherical anisotropic patterns of the Earth's inner core.
abstract: It has been shown that the Earth's inner core has an axisymmetric anisotropic structure with seismic waves traveling approximately 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 [111] 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.
authors.affiliation: Departamento de Física de la Tierra, Astronomía y Astrofísica I, Universidad Complutense de Madrid, E-28040 Madrid, Spain. mmattesi@fis.ucm.es
authors.forename: Maurizio
authors.initials: M
authors.lastname: Mattesini
authors.forename: Anatoly B
authors.initials: AB
authors.lastname: Belonoshko
authors.forename: Elisa
authors.initials: E
authors.lastname: Buforn
authors.forename: María
authors.initials: M
authors.lastname: Ramírez
authors.forename: Sergei I
authors.initials: SI
authors.lastname: Simak
authors.forename: Agustín
authors.initials: A
authors.lastname: Udías
authors.forename: Ho-Kwang
authors.initials: HK
authors.lastname: Mao
authors.forename: Rajeev
authors.initials: R
authors.lastname: Ahuja
references.citation: Phys Rev Lett. 2009 Aug 14;103(7):078501
references.pmid: 19792692
references.citation: Nature. 2001 Sep 6;413(6851):57-60
references.pmid: 11544523
references.citation: Science. 2000 Mar 31;287(5462):2471-4
references.pmid: 10741963
references.citation: Science. 1993 Dec 10;262(5140):1708-11
references.pmid: 17781788
references.citation: Science. 1996 Nov 8;274(5289):963-6
references.pmid: 8875934
references.citation: Science. 2000 Jun 16;288(5473):2007-12
references.pmid: 10856207
references.citation: Phys Rev Lett. 2000 Apr 17;84(16):3638-41
references.pmid: 11019165
references.citation: Proc Natl Acad Sci U S A. 2002 Oct 29;99(22):14026-30
references.pmid: 12374869
references.citation: Science. 2006 Nov 10;314(5801):967-70
references.pmid: 17008488
references.citation: Nature. 2003 Jul 31;424(6948):536-9
references.pmid: 12891353
references.citation: Science. 2007 Jun 29;316(5833):1880-3
references.pmid: 17600212
references.citation: Science. 2007 Jun 15;316(5831):1603-5
references.pmid: 17569860
references.citation: Nature. 2002 Apr 11;416(6881):620-3
references.pmid: 11948347
references.citation: Science. 2008 Feb 8;319(5864):797-800
references.pmid: 18258912
references.citation: Nature. 2003 Aug 28;424(6952):1032-4
references.pmid: 12944963
references.citation: Science. 1995 Mar 31;267(5206):1972-5
references.pmid: 17770110
references.citation: Science. 1999 Nov 19;286(5444):1547-1549
references.pmid: 10567258
references.citation: Phys Rev B Condens Matter. 1996 Oct 15;54(16):11169-11186
references.pmid: 9984901
references.citation: Science. 2003 Jan 24;299(5606):552-5
references.pmid: 12543971
references.citation: Nature. 2005 May 26;435(7041):483-7
references.pmid: 15917806
references.citation: Nature. 2001 Apr 26;410(6832):1081-4
references.pmid: 11323668
references.citation: Nature. 2001 Sep 6;413(6851):60-3
references.pmid: 11544524
references.citation: Phys Rev B Condens Matter. 1994 Sep 1;50(9):5918-5927
references.pmid: 9976960
references.citation: Nature. 2008 Aug 14;454(7206):873-6
references.pmid: 18704084