Australian researchers discover doughnut-shaped region inside Earth’s core

CANBERRA, Aug. 31 (Xinhua) — Australian researchers have discovered a doughnut-shaped region within the Earth’s liquid core that could deepen the understanding of the planet’s magnetic field.
In a study published on Saturday, a team of seismologists from the Australian National University (ANU) detected the region thousands of kilometers below the Earth’s surface near where the outer liquid core meets the mantle.
Hrvoje Tkalcic, co-author of the study from the Research School of Earth Sciences (RSES) at the ANU, said that the newly discovered region sits parallel to the equator and is only found at low latitudes.
“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,” he said in a media release.
Researchers discovered the region by analyzing waveforms generated by earthquakes for several hours after the origin times of large seismic events.
Tkalcic said the region had remained hidden until now because previous studies collected data with less volumetric coverage of the liquid outer core by observing seismic waves confined within one hour of large earthquakes.
Co-author Ma Xiaolong, a postdoctoral researcher at the RSES who completed his PhD at the Chinese Academy of Sciences, said the discovery solves some mysteries about the dynamics of the Earth’s magnetic field.
The research team believes that knowing more about the composition of the Earth’s core is fundamental to understanding the magnetic field and predicting when it will cease or weaken.
“The magnetic field is a fundamental ingredient that we need for life to be sustained on the surface of our planet,” Tkalcic said.
He said that the findings could promote more research about the magnetic field of Earth and other planets. ■