There are three reasons why our planet wobbles: glacial rebound, melting of ice, and mantle convection, according to a study published in the journal Earth and Planetary Science Letters.
WORLD (Next Media) – There are three reasons why our planet wobbles: glacial rebound, melting of ice and mantle convection, according to a study published in the journal Earth and Planetary Science Letters.
Earth’s shape and weight distribution isn’t perfectly even, due to the mountains and glaciers on Earth’s surface. Large glaciers, such as Antarctica or the Arctic, compress the earth which causes the sides of the planet to bulge outward.
As the glaciers start to melt, the land would gradually start to regain its original shape. This process is referred to as glacial rebound and was found to only be responsible for about 3.5 centimeters of axis wobble each year.
Scientists used to believe glacial rebound was the main reason why Earth would wobble.
NASA found the melting of the ice, fueled by the release of greenhouse gases, accounted for one third of Earth’s wobble.
Mantle convection also affects the planet’s spin as molten rock rises and falls and can redistribute Earth’s mass.
NASA says the planet’s wobble will continue to increase as the combination of these three factors continue to affect Earth.
However, they added the wobble isn’t large enough to impact ecosystems…for now.
Associated LinksGeologyEarthGeodynamicsPlanetary scienceGlaciologyGeological history of EarthGeomorphologyPost-glacial reboundMantleConvectionPlate tectonics