Discoveries

February 06, 2023

Spinning Backward

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A new study theorizes that Earth’s inner core has reversed its rotation, the Wall Street Journal reported.

Chinese researchers have analyzed earthquake-driven seismic waves as they pass through the Earth since the 1960s. Their findings suggest that between 2009 and 2020, the inner core’s rotation stopped and changed course.

The team explained that the inner core is made out of iron and nickel, adding that it remains separated from the rest of the planet by the liquid outer core – subsequently allowing it to rotate differently than the rest of the planet.

The liquid outer core generates a magnetic field, which causes the inner core to spin.

While the findings might cause some panic, researchers suggested that this rotational shift could have been going on for a long time, but has only been detected recently.

They noted that the reversal would shorten the length of the day by a fraction of a millisecond over the course of a year and incrementally affect Earth’s magnetic field.

Fortunately, it will not impact life on the planet.

Understanding how the inner core spins can help scientists in determining how the Earth’s many layers interact with one another.

Even so, other researchers pointed out that the study is still theoretical and there may be other interpretations of the seismic data.

“They have a very good analysis and the theory they put in the papers is probably as good as anything at the moment, but there are several competing ideas as well,” according to Earth science professor, John Vidale, who was not involved in the study.

This story originally appeared in the February 06, 2023 newsletter, Straddling a Divide.