Multiscale inhomogeneities on the surface of the Earth's inner core

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Abstract

The analysis of differential travel-time residuals of reflected PcP and PKiKP waves that probe the core regions under Eurasia, Southeast Asia, and South America indicates a mosaic picture of the surface properties of the inner core, including large-scale and small-scale lateral inhomogeneities. A strong anomaly has been discovered under the Caspian Sea.

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About the authors

V. M. Ovtchinnikov

Sadovsky Institute of Geosphere Dynamics, Russian Academy of Sciences

Author for correspondence.
Email: ovtch@idg.ras.ru
Russian Federation, Moscow

O. A. Usoltseva

Sadovsky Institute of Geosphere Dynamics, Russian Academy of Sciences

Email: kriukova@mail.ru
Russian Federation, Moscow

References

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Supplementary files

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2. Fig. 1. Fragments of seismograms of the Pamir-Hindu Kush earthquake of August 8, 2019 at seismic stations: (a) in Kazakhstan and Kyrgyzstan, (b) in Turkey, (c) in Eastern Siberia.

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3. Fig. 2. Map of earthquake foci (red stars), seismic stations (triangles) and projections of reflection points (yellow hexagons) from the inner core of PKiKP waves. The inset shows a diagram of rays for PcP and PKiKP waves.

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4. Fig. 3. Spatial distribution of ddt on a large-scale world map and small-scale details in three regional insets: (a) Argentina, (b) Mongolia, (c) Chukotka. Red lines indicate low-velocity zones in the D” layer of the lower mantle, and green lines indicate zones of tectonic disturbances in the earth’s crust. Ovals indicate data on nuclear explosions [8].

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5. Fig. 4. Variations in differential travel times and the amplitude ratio of PKiKP and PcP waves observed at seismic stations in Japan during the Okhotsk Sea earthquake on May 24, 2013. Circles indicate variations in the amplitude ratio, asterisks indicate variations in differential travel time residuals.

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