Seismologists now believe that the Earth's core oscillates rather than just rotating at a constant speed.
Their data is derived from records of nuclear explosions that occurred underground throughout the 20th century.
It has long been believed by scientists that Earth's core not only rotates, but spins more quickly than the surface. But according to recent study from the University of Southern California (USC),
which was published last week in Science Advances, the Earth's core moves more slowly than the planet's surface and even reverses course roughly every six years.
This movement pattern challenges decades of research by showing that the Earth's core oscillates in reality.
According to a news statement from USC earthquake researcher John Vidale, "the inner core is not fixed—it is moving under our feet, and it seems to travelling back