Phys.org August 30, 2024
Thermochemical inhomogeneities in the Earth’s outer core that enhance our understanding of the geodynamo have been elusive. Seismic constraints on such inhomogeneities would provide clues on the amount and distribution of light elements in the core apart from iron and nickel. Researchers in Australia found evidence for a low-velocity volume within the outer core via the global coda correlation wavefield. Several key correlogram features with a unique sensitivity to the liquid core showed variations with wave paths remarkably slower in the equatorial than polar planes constrained a torus structure at low latitudes with lower velocity than the surrounding liquid outer core via waveform modeling. The researchers proposed a thermochemical origin for such a low-velocity torus, providing important constraints on the dynamical processes of the Earth’s outer core… read more. Open Access TECHNICAL ARTICLE
Comparisons of the polar and equatorial groups’ waveforms… Credit: Science Advances, 30 Aug 2024, Vol 10, Issue 35