Skip to Main content Skip to Navigation
New interface
Journal articles

Constraints on Inner Core Anisotropy Using Array Observations of P'P'

Abstract : Recent studies of PKPdf travel times suggest strong anisotropy (4% or more) in the quasi-western inner core hemisphere. However, the availability of paths sampling at low angles to the Earth's rotation axis (the fast axis) is limited. To augment this sampling, we collected a travel time data set for the phase P'P'df (PKPPKPdf), for which at least one inner core leg is quasi-polar, at two high latitude seismic arrays. We find that the inferred anisotropy is weak (on the order of 0.5 to 1.5%), confirming previous results based on a much smaller P'P' data set. While previous models of inner core anisotropy required very strong alignment of anisotropic iron grains, our results are more easily explained by current dynamic models of inner core growth. We observe large travel time anomalies when one leg of P'P'df is along the South Sandwich to Alaska path, consistent with PKPdf observations, and warranting further investigation.
Document type :
Journal articles
Complete list of metadata
Contributor : Nathalie POTHIER Connect in order to contact the contributor
Submitted on : Wednesday, August 10, 2022 - 1:28:25 PM
Last modification on : Tuesday, October 25, 2022 - 12:49:19 PM
Long-term archiving on: : Friday, November 11, 2022 - 6:45:51 PM


Geophysical Research Letters -...
Publisher files allowed on an open archive





Daniel A. Frost, Barbara Romanowicz. Constraints on Inner Core Anisotropy Using Array Observations of P'P'. Geophysical Research Letters, 2017, 44, pp.10,878-10,886. ⟨10.1002/2017GL075049⟩. ⟨insu-03748829⟩



Record views


Files downloads