[Rockhounds] Doughnut-shaped region found inside Earth's core deepens understanding of planet's magnetic field

[Kreigh Tomaszewski]

A doughnut-shaped region thousands of kilometers beneath our feet within
Earth's liquid core has been discovered by scientists from The Australian
National University (ANU), providing new clues about the dynamics of our
planet's magnetic field.

The structure within Earth's liquid core is found only at low latitudes and
sits parallel to the equator. According to ANU seismologists, it has
remained undetected until now.

The Earth has two core layers: the inner core
<https://phys.org/tags/inner+core/>, a solid layer, and the outer core, a
liquid layer. Surrounding the Earth's core is the mantle. The newly
discovered doughnut-shaped region is at the top of Earth's outer core,
where the liquid core meets the mantle.

Study co-author and ANU geophysicist, Professor Hrvoje Tkalčić, said the
seismic waves detected are slower in the newly discovered region than in
the rest of the liquid outer core.

"The region sits parallel to the equatorial plane, is confined to the low
latitudes and has a doughnut shape," he said.

"We don't know the exact thickness of the doughnut, but we inferred that it
reaches a few hundred kilometers beneath the core-mantle boundary."

https://phys.org/news/2024-08-doughnut-region-earth-core-deepens.html#google_vignette