Comment on the article “Probability of radial anisotropy in the deep mantle” by Visser et al. (2008)

Earth and Planetary Science Letters 276 (2008) 223–225Contents lists available at ScienceDirectEarth and Planetary Science Lettersjournal homepage: www.elsevier.com/locate/epslDiscussionComment on the article “Probability of radial anisotropy in the deep mantle”by Visser et al. (2008) EPSL 270:241–250⁎Andréa Tommasi , David MainpriceGeosciences Montpellier, CNRS & Université Montpellier 2, CC.060, Pl. Eugène Bataillon, Montpellier, F-34095, Francearticle infoArticle history:Accepted 17 July 2008Available online 17 September 2008Editor: R.D. van der HilstBased on the inversion of a large surface waves dataset, including Strong anisotropy at the rock scale is produced when the crystalboth fundamental and higher modes, Visser et al. (2008) constructed preferred orientations have strong single maxima concentrations ofnew maps of the probability of surface wave polarization (or radial) the crystallographic directions corresponding to the highest andanisotropy. These maps bring new constraints on the variation of lowest propagationvelocities or S-wavesplittingof thesingle crystal.radial anisotropy with depth as a function of the geodynamic This is the case, for instance, for olivine under shallow mantleenvironment. However, the interpretation of the seismic anisotropy conditions, where dislocation creep with dominant activation of thedistributionin terms of mantledeformation is oversimplified, sinceit (010)[100] slip system leads to a strong orientation of ...