Scientists say Earth’s inner core has changed its rotation – Saudi Gazette

Scientists say Earth’s inner core has changed its rotation – Saudi Gazette

LONDON —The Earth’s core may have stopped spinning, or may even now be spinning backwards, according to a new study.

The core of our planet is made up of an outer layer of liquid metal, and an inner core of solid metal that is about 70 percent the size of the Moon.

It is generally believed that the core rotates counter-clockwise when viewed from the North Pole, like the rest of planet Earth.

But a study analyzing seismic wave data over the past 60 years by researchers at Peking University in China has concluded that the core’s rotation stopped around the year 2009, and then restarted in the opposite direction.

“We think that the core is, relative to the surface of the Earth, rotating in one direction and then the other, like a swing,” Xiaodong Song and Yi Yang, the study authors, told AFP.

A complete cycle (in one direction and then the other) of this swing is about 70 years, they added.

According to the researchers, the last rotation change before 2009 would have occurred in the early 1970s, and the next one will take place in the mid-2040s.

There is still much debate about the nature of the Earth’s core, because gathering information on it