On the orientation of the fast and slow directions of anisotropy in the deep inner core

  title={On the orientation of the fast and slow directions of anisotropy in the deep inner core},
  author={Daniel A. Frost and Barbara A. Romanowicz},
  journal={Physics of the Earth and Planetary Interiors},

Evidence for the Innermost Inner Core: Robust Parameter Search for Radially Varying Anisotropy Using the Neighborhood Algorithm

The model of cylindrical anisotropy in the inner core (IC) states that seismic rays traveling parallel to the Earth's rotational axis travel faster than those parallel to the equator. There have been

Dynamic history of the inner core constrained by seismic anisotropy

Progressive crystallization of Earth’s inner core drives convection in the outer core and magnetic field generation. Determining the rate and pattern of inner-core growth is thus crucial to

A New Probe Into the Innermost Inner Core Anisotropy via the Global Coda‐Correlation Wavefield

Investigations of the Earth's inner core (IC) using seismic body waves are limited by their volumetric sampling due to uneven global distribution of large earthquakes and receivers. The sparse

Inner core anisotropy measured using new ultra-polar PKIKP paths

We measure the seismic anisotropy of the inner core using PKPbc-PKPdf and PKPab-PKPdf differential traveltimes, as a function of the angle ζ between the Earth’s rotation axis and the ray path in

3D Transdimensional Seismic Tomography of the Inner Core

<p>The inner core contains strong seismic heterogeneity, both laterally and from the surface to the centre. Accurately resolving the seismic structure of the inner core is key to unravelling the

Early Cambrian renewal of the geodynamo and the origin of inner core structure

Paleomagnetism can elucidate the origin of inner core structure by establishing when crystallization started. The salient signal is an ultralow field strength, associated with waning thermal energy

Upper mantle slab under Alaska: contribution to anomalous core-phase observations on south-Sandwich to Alaska paths



Anisotropy of the Earth's inner core

The inner core has the intriguing property that seismic waves traveling parallel to the Earth's spin axis arrive earlier than those traveling parallel to the equatorial plane. The travel time is some

Large-scale variations in inner core anisotropy

I analyze nearly 2000 handpicked differential times of core-penetrating compressional waves to image lateral variations in the anisotropic structure of the solid inner core. The inner core is

Inner core anisotropy in three dimensions

The purpose of this paper is the investigation of cylindrical anisotropy in the inner core based on the travel time anomalies of the PKIKP phase. We use the arrival times reported in the

Hemispherical structure in inner core velocity anisotropy

[1] We investigate the hemispherical pattern in inner core velocity anisotropy using a new and independent high-quality data set of PKPbc-PKPdf and PKPab-PKPdf body wave observations. Our data show

Evidence for inner core anisotropy from free oscillations

Previous hypotheses concerning the cause of anomalous splitting in free oscillation spectra have led to models which are difficult to accept from the physical point of view - involving either

Anisotropy in the center of the inner core

We have assembled a collection of PKP data from broadband records of the Geoscope network. This collection is unique because, for the first time, it includes polar paths at epicentral distances

Seismic anisotropy in the Earth's innermost inner core: Testing structural models against mineral physics predictions

Using an updated data set of ballistic PKIKP travel time data at antipodal distances, we test different models of anisotropy in the Earth's innermost inner core (IMIC) and obtain significantly better

The innermost inner core of the earth: Evidence for a change in anisotropic behavior at the radius of about 300 km

  • M. IshiiA. Dziewoński
  • Geology, Physics
    Proceedings of the National Academy of Sciences of the United States of America
  • 2002
The existence of an innermost inner core, with a radius of ∼300 km, that exhibits a distinct transverse isotropy relative to the bulk inner core is proposed, which may represent fossil evidence of a unique early history of inner-core evolution.

Growth model of the inner core coupled with the outer core dynamics and the resulting elastic anisotropy

We present a growth tectonic model of Earth's inner core and the resulting model of the seismic anisotropy. The inner core grows anisotropically if the convection in the outer core is of Taylor