“the solid inner core of the Earth, a hot iron ball, stopped paused and began to rotate in the opposite direction,” NASA stated in a statement.
The earth’s center is approximately 5,000 kilometers (3,100 miles) under the surface we live on, this “planet within the planet” is able to spin independently because it floats in the liquid metal outer core, an AFP report said.
Scientists have been fighting for a long time about the mechanism by which the inner core rotates, and the most recent research is likely to raise questions about this process.
The little we know about the inner core originates from measuring the small disparities in seismic waves as they travel through the center of the Earth, brought on by earthquakes or often nuclear explosions.
Trying to keep track of the inner core’s movements, new research published in the journal Nature Geoscience examined seismic waves from saying earthquakes during the last 6 years.
The editors, Xiaodong Song and Yi Yang of Peking University in China, said the inner core “came to a near halt’ and “then turned in an opposite direction” after the 2009 study.
“the intrinsic core of the earth flexes as a swing forth and back, relative to the surface area of the earth,” the scientists told AFP.
“One cycle of the swing is about 7 decades”, which means it changes direction roughly every thirty five years, they added.
They mentioned it had changed course before during the early 1970s and predicted the next about-face would come in the mid-2040s.
Researchers say their rotation roughly lines up with variations in what is called the “length of day” — little variations in the exact time Earth rotates on its axis.
Up to now, there is little evidence that shows how much exactly the inner core actually does have many effects on the surface dwellers.
Researchers think there’re connections between all the layers of the Earth, from the inner core to the outer layer.
“our study can inspire some researchers to create and test models which treat the whole Earth as an integrated dynamic system,” it said in a statement.
Scientists have expressed caution regarding the findings, pointing to a number of other theories and warning that lots of mysteries remain about the center of the Earth.
“This is a really thorough study by excellent scientists putting in a great deal of data,” John Vidale, a seismologist at the University of Southern California, said.
“However, not one of the models explain all of the information very well in my opinion,” he said.
Vidale published research last year indicating the inner core oscillates a lot more fast, changing direction every six years or so. His research was derived from seismic waves from two nuclear explosions in the late 1960s and early 1970s.
That timeframe is around the point when Monday’s analysis says the inner core last altered direction — which Vidale called “kind of a coincidence”.
Another theory — which Vidale said has some good evidence supporting it — is the fact that the inner core just considerably moved between 2001 to 2013 and has remained there since.
Hrvoje Tkalcic, a geophysicist at the Australian National University, has published research indicating that the inner core’s cycle is every 20 to 30 years, rather than the 70 suggested in the latest analysis.
These mathematical models are probably all incorrect since they explain the observed information, but are not required by the data, Tkalcic said.
“The geophysical community is going to be divided about this finding, and the subject will stay controversial,” he said.
Seismologists, he said, “study the inner organs of patients ‘bodies using inadequate or limited equipment.”
Without something such as a CT scan, “our picture of the inner Earth continues to be blurry”, he said, predicting more surprises ahead.
That might consist of a theory that the inner core may have another iron ball like a Russian doll within it.
“Something is happening, and I do think we are going to figure it out,” Vidale said.
“But it may take a decade.”