London, May 6 (ANI): Fluctuations at Earth”s core decide the length of the day, according to scientists.
To come up with the finding, Nicolas Gillet of the University of Joseph Fourier in Grenoble, France, and colleagues, modelled fluid behaviour in the Earth”s core based on measurements of fluctuations in the magnetic field.
According to Gillet, the innermost region of the Earth”s outer core periodically flows faster or slower, and this action “tugs” at the planet”s magnetic field.
New Scientist reports, “the field then pulls the region back towards its original position. But the effect ripples outward, changing the core”s rate of rotation layer by layer.
“The researchers calculated how this would affect the rotation rate of the whole planet, which would compensate to conserve angular momentum.
“They found the day length varies by 0.4 milliseconds over a six-year period. This fits with day-length measurements taken between 1925 and 1997.
“The twisting had previously been blamed for a 60-year cycle in day length, but the rate of rotation found in this study suggests it is not the culprit, says Jon Mound at the University of Leeds, UK.” (ANI)