The Peculiarities of the Earth’s Outer-to-Inner Core Transition Zone from the Characteristics of PKIIKP and PKP c-dif Waves

Abstract—The structure of seismic wavefield at distances close to antipodal is analyzed using two numerical methods—DSM and AXISEM—for calculating full waveforms. The obtained empirical estimates of the amplitude ratio of PKIIKP and PKIKP phases indicate that the S-wave velocity in the upper 40 km of the inner core may not be higher than 3.1 km/s. The properties of the PKPc-dif waves suggest a lower P-wave velocity in the lower 100 km of the outer core.

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Correspondence to V. M. Ovtchinnikov.

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Translated by M. Nazarenko

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Usoltseva, O.A., Ovtchinnikov, V.M. & Krasnoshchekov, D.N. The Peculiarities of the Earth’s Outer-to-Inner Core Transition Zone from the Characteristics of PKIIKP and PKP c-dif Waves. Izv., Phys. Solid Earth 57, 84–97 (2021). https://doi.org/10.1134/S1069351321010109

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Keywords:

  • complete synthetic seismograms
  • antipode
  • PKIIKP and PKP c-dif waves
  • inner core
  • outer core