New Research Reveals Intricate “Tapestry” in Earth’s Inner Core
A team of researchers from the University of Utah has made an intriguing discovery about Earth’s inner core. Contrary to previous assumptions, the inner core is not a homogenous mass but rather a complex “tapestry” of different fabrics. This groundbreaking research provides new insights into the formation, evolution, and creation of Earth’s protective magnetic field.
The study, published in the journal Nature, utilized seismic data from earthquakes and sensing instruments from CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organization) to analyze the inner core. The team found evidence suggesting that the inner core initially grew rapidly, but its growth slowed down over time. Furthermore, the researchers propose that there may be liquid iron trapped within the inner core.
The inner core, located at the center of Earth, is a solid metal ball often referred to as a “planet within a planet.” Its existence is essential for life on the surface as it plays a crucial role in generating Earth’s magnetic field.
Keith Koper, a seismologist from the University of Utah, explained that studying the inner core is like exploring a frontier area. The deepest part of Earth is challenging to image, but seismic waves from earthquakes provide valuable insights. The researchers utilized data from the International Monitoring System (IMS), which monitors seismic activity to detect nuclear blasts. This dataset allowed them to study the inner core’s intricate structure.
Previous studies conducted by the same team identified variations in Earth’s rotation and the inner core, contributing to a shift in the length of the day from 2001 to 2003. Now, their new study reveals the inhomogeneity within the inner core itself.
The protective magnetic field surrounding Earth is generated by convection within the liquid outer core. The circulation of molten iron generates electron bands that envelop the planet. Without the solid inner core, this magnetic field would be weaker, exposing the surface to harmful radiation and solar winds.
To conduct their research, the team analyzed seismic waves from over 2,400 earthquakes exceeding a magnitude of 5.7. They found that the inhomogeneity within the inner core is stronger at deeper layers, indicating how fast the inner core grew in the past. The inner core is estimated to have grown rapidly, reached an equilibrium, and then significantly slowed down. Some liquid iron may still be trapped within the solid core.
The study contributes to a deeper understanding of Earth’s interior and sheds light on its formation and evolution. The research was funded by the National Science Foundation and included scientists from the University of Southern California, the Université de Nantes in France, and the Los Alamos National Laboratory.
This groundbreaking research challenges previous assumptions about Earth’s inner core and paves the way for further exploration into the mysteries of our planet’s deep interior.