A new study by two researchers from Peking University suggests that over the past ten years, the rotation of the Earth’s inner core may have stopped, and possibly even started, to spin backward.
According to the geophysicists’ research, the Earth’s inner core oscillates roughly every seven decades, which is synchronised with changes in the length of the day, the strength of the planet’s magnetic field, as well as global sea levels and temperatures, South China Morning Post reported.
The researchers concluded that “the Earth appears to function as a resonant system that encompasses all of the primary layers of the solid earth, from the surface to the inner core.” On Tuesday, the team published its findings in the peer-reviewed journal Nature Geoscience.
The examination of data spanning six decades, according to the author Yang Yi, an associate research scientist at the SinoProbe Laboratory and Institute of Theoretical and Applied Geophysics, revealed that the Earth’s inner core was “rather stable” between 1964 and 1980.
From that point on, the inner core accelerated and rotated more quickly than the Earth, which revolves around its axis, until 2009, when it stopped. Yang claimed that since since, the Earth’s rotation has been reversed because the inner core has been spinning more slowly than it.
A similar reversed rotation was reportedly seen in the early 1970s as well, which suggests an oscillating pattern of six to seven decades, according to the research team.
“We show surprising observations that indicate the inner core has nearly ceased its rotation in the recent decade and may be experiencing a turning-back in a multidecadal oscillation, with another turning point in the early 1970s,” they wrote.
The study claimed that similar oscillations can be observed in geomagentics, fluctuations in day length, and shifts in the average world temperature and sea level over a 60 to 70-year period.
The findings, according to co-author Song Xiaodong, chair professor at Peking University’s school of earth and space sciences, demonstrated that variations in the Earth’s interior core were directly related to variations in temperature and sea level.
“The Earth is a special planet in our solar system – it is covered in liquid water, inhabited and surrounded by a magnetic field. The rotation of the inner core, like that of the planet, is an important parameter of the Earth,” he said.
While the Earth rotates once in about 24 hours, the Earth’s inner core has a different rotation period from the outer Earth layers.
The Earth’s core, mostly made up of iron alloy, is about 2,900km (1800 miles) below the Earth’s surface. The Earth’s solid inner core, which has a temperature of around 5,200 degrees Celsius (9,392 Fahrenheit), is separated from the solid mantle by a liquid outer core and rotates inside the planet.
