In the distance, under the earth’s surface, a giant may have begun to rotate in a different direction from ours, according to a study, whose conclusions should not end the controversy that agitates experts.
The Earth’s core, a sphere the size of Pluto, has stopped rotating and may even have begun to rotate in the opposite direction, suggests this study, published Tuesday in the journal Nature Geoscience.
This essentially iron ‘planet on planet’, some 5,000 kilometers from the surface, is free to move as it floats in the liquid envelope of the outer core.
The exact mechanism of this rotation continues to fuel debate. The little that is known is based on the analysis of seismic waves, caused by earth tremors, when they pass through the center of the planet.
By analyzing these waves over the past 60 years, Xiaodong Song and Yi Yang of Peking University concluded that the core’s rotation “almost stopped in 2009, before restarting in the opposite direction.”
“We think the central core rotates, relative to the Earth’s surface, in one direction and then the other, like a swing,” they told AFP.
“A complete cycle is about 70 years,” according to his estimates. The last rotation change prior to that of 2009 had occurred in the 1970s. The next, always according to these scientists, should occur in the 2040s.
This rotation, in his opinion, would be more or less reflected in changes in the length of days, small variations in the extra time it takes for the planet to rotate on its axis.
To date, there is little indication of the influence this rotation has on what happens on the Earth’s surface.
Source: TSF
