Fig. 4: Schematic diagram of the IC geomagnetic field and depth-dependent anisotropic texture change in comparison with the calculated velocity anisotropy in FeH0.25.
From: Superionic effect and anisotropic texture in Earth’s inner core driven by geomagnetic field
a Poloidal (BP) and toroidal (BT) fields in the IC in the meridional plane. BP is shown with red curves in the right sphere, and BT is shown with blue curves in the left sphere. The dashed purple line is the rotation axis. The thick black line is the PKIKP ray path. PKIKP refers to the compressional wave path transmitted through the inner core. The angle between the ray path and Earth’s rotation axis is ξ. The isotropic layer at the UIC is shown with a yellow region. The deeper layer presenting the slowest velocity in the equatorial direction is shown with the blue region. The IMIC with the slowest angle of ~ 45–50° from Earth’s rotation axis is shown with a green region. b PKPab-PKIKP travel-time residuals15 as a function of angle ξ are compared with the calculated compressional wave velocity anisotropies in the AEP (black curves) and IEP (blue curves) models. PKPab is the reference seismic wave phase traversing only the mantle and outer core. The data travelling from the South Sandwich Islands (SSI) to Alaska are shown with red crosses. c Calculated velocity anisotropy in FeH0.25 in comparison with the velocities of PREM52 (1221 km, red dashed line) and the anisotropic IMIC (920–1221 km, green and orange dashed curves) modes13,38.
