Earth’s Mysterious Inner Core

Weekly Earths Inner Core: The hidden movements

• In the year 1971 and 1974, the Soviet Union organized two separate nuclear tests in northern Russia to examine and detect backscattered seismic waves.
• The pinging was so powerful that the signal waves bounced from the inner core and were transmitted 4,000 miles away in Montana. They were also detected by seismic stations around the world.
• John Vidale from the University of Southern California attempted to calculate the inner core’s super-rotation.
• Using the LASA data and calculating the motion of the inner core based on the seismic waves, Vidale approximated that it rotated 0.07 degrees longer than the rest of the planet each year between 1971 and 1974.
• In the year 2000, Vidale retested the data that was detected by the Montana array and found out that a faster super-rotation was calculated of 0.15 degrees per year.