[ad_1]
A new study says Earth’s core has slowed over the past two decades, and that could be having a measurable impact on the planet.
The University of Southern California said new evidence shows that Earth’s inner core — a hard, moon-sized iron-nickel ball at the center of the planet — has been slowing down since 2010.
“When I first saw the seismograms that hinted at this change, I was stunned,” said John Vidale, Dean’s professor of earth sciences.
“But when we found two dozen more sightings signaling the same pattern, the result was inescapable.
“The inner core has slowed down for the first time in many decades.”
The inner core is thought to be turning relative to the planet’s surface due to it moving slightly slower instead of faster than Earth’s mantle – the massive layer between the planet’s solid crust and outer core – for the first time for about 40 years.
Vidale said the slowing of the inner core is caused by the churning of the liquid iron outer core, which generates Earth’s magnetic field, as well as the gravitational pull from dense regions of the overlying rocky mantle.
The implications of the findings can only be speculated, the researchers said.
Vidale said the inner core’s retrograde can change the length of the day — but only by fractions of a second.
Origin of mysterious space debris found in US mountains revealed
“It’s very hard to spot, on the order of thousandths of a second, almost lost in the noise of the agitated oceans and atmosphere,” he said.
Now USC scientists hope to determine exactly why the inner core shifts.
“The dance of the inner core may be even more lively than we know so far,” Vidal said.
[ad_2]
