Dec 16, 2024 05:19 PM
https://www.sciencenews.org/article/inne...hape-earth
EXCERPTS: Earth’s inner core, a solid metal ball gyrating within the molten outer core, may be both slowing down and changing shape. Recent analyses of earthquake waves have suggested that around 15 years ago, the inner core’s rotation may have slowed so much that it appeared to pause or reverse direction relative to the surface. But a new analysis suggests something more must be changing at Earth’s center.
The most probable explanation is that the inner core is not only rotating differently — its surface is probably also morphing, geophysicist John Vidale of the University of Southern California in Los Angeles reported December 9 at a meeting of the American Geophysical Union. The finding could help resolve a long-standing debate over what is changing at the inner core.
[...] It’s possible that the entire geoid-shaped inner core is deforming, like a football being reshaped so its ends point in two new directions. Alternatively, he says, patches of the inner core’s surface may be swelling or contracting. That would be like small bumps and dents forming on the metaphorical football. It’s also possible that both processes are occurring. Such changes could be driven by the gravitational pull of the mantle — Earth’s largest internal layer — or by material flowing in the outer core, Vidale says.
This is not the first time researchers have reported that the inner core’s surface changes over time. [...] As for how all of this affects life on Earth, “we don’t know that this is going to affect anything on the surface,” Vidale says. “But we can’t say for sure until we figure out what’s happening.” (MORE - missing details)
EXCERPTS: Earth’s inner core, a solid metal ball gyrating within the molten outer core, may be both slowing down and changing shape. Recent analyses of earthquake waves have suggested that around 15 years ago, the inner core’s rotation may have slowed so much that it appeared to pause or reverse direction relative to the surface. But a new analysis suggests something more must be changing at Earth’s center.
The most probable explanation is that the inner core is not only rotating differently — its surface is probably also morphing, geophysicist John Vidale of the University of Southern California in Los Angeles reported December 9 at a meeting of the American Geophysical Union. The finding could help resolve a long-standing debate over what is changing at the inner core.
[...] It’s possible that the entire geoid-shaped inner core is deforming, like a football being reshaped so its ends point in two new directions. Alternatively, he says, patches of the inner core’s surface may be swelling or contracting. That would be like small bumps and dents forming on the metaphorical football. It’s also possible that both processes are occurring. Such changes could be driven by the gravitational pull of the mantle — Earth’s largest internal layer — or by material flowing in the outer core, Vidale says.
This is not the first time researchers have reported that the inner core’s surface changes over time. [...] As for how all of this affects life on Earth, “we don’t know that this is going to affect anything on the surface,” Vidale says. “But we can’t say for sure until we figure out what’s happening.” (MORE - missing details)