A groundbreaking study reveals the Earth’s inner core may be undergoing a mysterious shape-shifting process, challenging our current understanding of this enigmatic region.
The Inner Core’s Shape-Shifting Mystery
Recent analyses of earthquake waves have shed new light on the Earth’s inner core, a solid metal ball that rotates within the molten outer core. The findings suggest that the inner core may not only be rotating differently but also changing its shape over time.
Seismologists use seismic waves from earthquakes to study the Earth’s core, as no instrument can physically probe it. By analyzing waveforms recorded at different receiver arrays in Alaska and Canada, researchers have identified subtle differences between similar-sized quakes that occurred in the same place but at slightly different times. These differences are thought to be caused by deformation of the inner core’s surface.
A Shifting Geoid?
The simplest explanation for these changes is that the entire geoid-shaped inner core is deforming, like a football being reshaped to have its ends point in two new directions. Alternatively, it may be that patches of the inner core’s surface are swelling or contracting, creating small bumps and dents.
Geophysicist Lianxing Wen of Stony Brook University reported similar changes in 2006, suggesting that material was exiting the inner core as it cooled. However, unlike his findings, other researchers like Xin Zhang of the University of Science and Technology of China maintain that the inner core does not rotate differently than Earth.
A Complex Picture
Geophysist Xiaodong Song of Peking University agrees with Vidale’s findings but notes that other processes, such as surface changes, may also be occurring. “It’s not either or,” he says. The exact mechanisms driving these changes are still unclear and require further study.
For now, the implications for life on Earth are uncertain. While the inner core’s shape-shifting may not directly affect the surface, understanding its dynamics is crucial for making informed decisions about our planet’s health.
Understanding the Inner Core
The Earth’s inner core is a complex system that has puzzled scientists for decades. By studying seismic waves and analyzing waveforms, researchers are gaining insights into the inner core’s behavior. However, there is still much to be learned about this enigmatic region of our planet.
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- sciencenews.org | Earth’s inner core may be changing shape
