Scientists Discover a Toroidal Region in Earth’s Liquid Outer Core, Shedding Light on Planetary Magnetic Mysteries.
A research team from the Australian National University (ANU) has discovered a toroidal region within Earth’s liquid outer core, located thousands of kilometers beneath the surface. The findings, published in the journal Science Advances, provide new insights into the dynamics of Earth’s magnetic field, as reported by Futurism on September 8. The internal structure of the liquid outer core has only been found at low latitudes, parallel to the equator. According to ANU seismologists, this region had never been recognized before.
The toroidal structure located in the outer core of the Earth. (Image: Studyfinds).
Earth has two core layers (solid inner core and liquid outer core). Surrounding the Earth’s core is the mantle. The newly discovered toroidal region sits at the top of the outer core, where the liquid core meets the mantle. Professor Hrvoje Tkalčić, a geophysicist at ANU, noted that seismic waves travel slower in this area compared to the rest of the outer core. Researchers are unsure of the exact thickness of the toroidal region, but they speculate it extends several hundred kilometers below the boundary between the outer core and the mantle.
Instead of using conventional seismic wave observation techniques and signals generated by earthquakes in the first hour following tremors, the ANU research team analyzed similarities in waveforms several hours after the earthquake began, leading to this remarkable discovery.
“By understanding the shape of the wave paths and how they propagate through the volume of the outer core, we reconstructed their travel times through the Earth, demonstrating that the newly discovered region has low seismic velocity,” Tkalčić explained. “This strange structure was previously obscured due to past research collecting data over a narrower range of the outer core by observing limited waves within one hour after a major earthquake.”
Dr. Xiaolong Ma, a co-author of the study, stated that the discovery reveals several mysteries about the dynamics of Earth’s magnetic field. The outer core is primarily composed of liquid iron and nickel, and the turbulent motion of this conductive fluid generates the magnetic field surrounding Earth, helping to sustain and protect all life from the effects of solar winds and harmful radiation. By gaining a better understanding of the composition of Earth’s outer core, including its chemical elements, scientists may be able to predict when the magnetic field will weaken or cease to function.
