Earth's inner core shows signs of 'deformation'

DNVN - Scientists have just announced an important discovery: The Earth's inner core - the solid metal part located deep below the liquid outer core - is not only changing its rotation speed but is also likely deforming.

John Vidale, a geophysicist at the University of Southern California in Los Angeles, presented the results of the study at the American Geophysical Union conference on December 9. The discovery has the potential to resolve long-standing debates about changes in the Earth's core.

Since scientists cannot directly study the Earth’s core, they use seismic waves from earthquakes as an analytical tool. They have focused on earthquakes in the South Sandwich Islands near Antarctica, an area opposite the measuring system in Alaska. Seismic waves, similar to sound waves traveling through water, can pass through the inner core before reaching the measuring stations.

In the study, Vidale’s team analyzed about 200 paired earthquakes that occurred between 1991 and 2024. The results showed slight differences in waveforms recorded at the Yellowknife, Canada, station, but not at Fairbanks, Alaska, suggesting that the inner core surface is showing signs of deformation.

Several hypotheses have been proposed to explain this phenomenon. One possibility is that the entire inner core is deforming, much like a rugby ball changing shape. Or, perhaps only certain areas of the surface are bulging or sinking, forming “bulges” and “dents.” These changes could be due to the gravitational pull of the tectonics—the largest part of the Earth—or to shifting material in the outer core.

Xiaodong Song, a geophysicist at Peking University who has previously detected differences in the inner core's motion compared to the rest of the Earth, agrees with Vidale's findings. He suggests that, in addition to changes in rotation, phenomena such as surface deformation may also be occurring at the same time. "It's not one or the other," he stresses.

According to Mr. Vidale, although it is not clear how these changes affect life on the Earth's surface, scientists will continue to conduct further research to clarify this phenomenon.

Thanh Mai (t/h)

Source: https://doanhnghiepvn.vn/cong-nghe/loi-trong-cua-trai-dat-co-dau-hieu-bien-dang/20241214081955496