One thing about science is that it is never "settled."
New research uncovered new evidence that requires jettisoning old theories and adopting new explanations for observed phenomena.
Take the Earth's core, for example. Once thought to be essentially "solid," it appears that the center of our planet is more dynamic than originally thought.
Scientists have discovered that the inner core's surface is changing shape, challenging previous assumptions about its solid nature. This dynamic activity could influence Earth's rotation and magnetic field
Deep within the Earth, a dramatic transformation is underway. A new study from the University of Southern California (USC), published in Nature Geoscience, has revealed evidence of significant structural changes occurring near the surface of Earth's inner core.
This discovery challenges previous assumptions about the inner core's composition and opens new avenues for understanding the planet's dynamics, including its rotation, magnetic field, and thermal history. The findings suggest that the inner core, previously thought to be a solid sphere, is far more dynamic and susceptible to change than previously imagined.
The inner core was previously thought of as solid.
Legal Insurrection readers may recall that I touched upon the subject in 2023 when it was noted that the inner core might be reversing its rotation and the position of the magnetic poles was changing.
This new study suggests that the core shape may be changing rather than just the relative rotation.
Scientists found evidence of this shape change by analyzing earthquake seismic waves that traveled through the Earth's core. The study revealed that the surface of the inner core, while solid, appears to be quite changeable over short periods. These changes were observed between 2004 and 2008, with some areas of the inner core possibly deforming by over 100 meters in height.
As a result of the study, new ideas about the core are being proposed. John Vidale, a professor of earth sciences at the University of Southern California and a contributor to the new study, suggests the outer core may be tugging at the inner one.
Turbulent flow in the outer core or gravitational pull from denser parts of the mantle could have deformed the inner core boundary, which might account for the change in the seismic signals, Dr. Vidale said.
"We expect it's soft because it's near melting point," he said. "So it's no surprise if it deforms."
The new findings will not be the last on the subject. "The offered interpretation is sound," said Hrvoje Tkalcic, a professor of geophysics at the Australian National University who was not involved with the research, "although it is not the only possible explanation, as the authors acknowledge."
In recent years, geophysicists have argued over whether differences in the seismic signals are caused by a change in the rotation rate or by a change in the shape of the inner core. "This study thus reconciles the last debate by proposing a combination of both causes," Dr. Tkalcic said.
How about the magnetic North Pole? It is currently drifting closer to Russia at a slightly slower pace than in the 1990s. Presently, it is north of east-central Siberia, continuing its drift away from Canada and towards Russia.