The seismological picture of the inner core: structure and rotation |
| |
Authors: | Annie Souriau Raphaël Garcia Georges Poupinet |
| |
Institution: | 1. Observatoire Midi-Pyrénées, CNRS, 14, av. Édouard-Belin, 31400 Toulouse, France;2. IPGP, Observatoire de Saint-Maur, 4, av. de Neptune, 94100 Saint-Maur-des-Fossés, France;3. LGIT, Observatoire de Grenoble, BP 53X, 38041 Grenoble cedex, France |
| |
Abstract: | This paper presents a review of recent results concerning the structure and the rotation of the inner core, as inferred from seismological observations. We first focus on the apparent hemispherical pattern of the inner core structure, observed in both the anisotropy and the heterogeneity of the uppermost layers, whereas isotropic velocities seem to be homogeneous in a broad wavelength domain. Then we present results on the radial variations of the attenuation and its possible anisotropy, for which viscoelasticity and wave scattering provide complementary explanations. Linked to these results is a discussion about the detection of the PKJKP phase, which propagates as S-wave inside the inner core. Finally, the seismological observations of a possible inner core rotation are discussed; recent results seem to favour rotation rates below 0.2° yr?1. |
| |
Keywords: | Seismology Inner core Anisotropy Attenuation Rotation Séismologie Noyau Graine Anisotropie Atténuation Rotation |
本文献已被 ScienceDirect 等数据库收录! |
|