The Earth is not an ultra-compact sphere that rotates in one piece. Its inner core, which is a Moon-sized piece of solid iron and nickel located more than 4,800 kilometers below the surface, is surrounded by a layer of molten metals (outer core). This layer is itself surrounded by a more solid sea of molten rock, called the mantle. Finally comes the earth’s crust
If everything is rotating, the inner core may do so at a slightly different speed than the mantle and crust due to the viscosity of the outer core. Measurements of its rotation speed began 40 years ago. Scientists then noted that the inner core rotated a little faster than the mantle and crust. But a new study published in “Nature” found that the inner core began to slow down in 2010 and that today, it rotates more slowly than the outer layers, as noted LiveScience.
According to the researchers, a slowdown in the rotation of the inner core could change its gravitational pull and cause a slowdown in the rotation of the Earth itself. And when the Earth rotates more slowly, it means an increase in the length of a day. Not enough to disrupt our lives, nor our clocks, since this change would only be of the order of a thousandth of a second.
The reasons for this slowdown are not very clear, but this phenomenon could in fact be regular, meaning that this slowdown is temporary before a further acceleration.
