It might only have a subtle effect, but it’s still measurable: the distribution of Earth’s glacial ice has an impact on how the planet spins, both in terms of the speed of our blue sphere’s rotation, and in the slow wobble that the Earth’s axis makes over it’s 26,000-year circle around the sky.
NASA has recently announced that the slow movement of the north pole, simply called polar motion, has changed towards an easterly direction toward England, as opposed to it’s usual southward progression toward Canada. The cause of this is the loss of mass being experienced in Greenland, and a change of the distribution of ice in Antarctica, where West Antarctica is losing ice mass and East Antarctica is gaining, resulting in the Earth being ever-so-slightly off-balance in relation to what it was before the 20th century. There’s no need to panic, however, as JPL’s researchers say that the shift is meaningful in terms of how we are impacting our planet, but the effect is subtle enough to ultimately be harmless.
The melting of the ice from the poles also means that that weight is slowly shifting towards the equator, affecting the speed of the Earth’s rotation. In a study released late last year, researchers from the University of Alberta found that the Earth’s rotation has slowed ever so slightly, with an effect similar to how spinning figure skaters will extend their limbs to slow their spin.
The team used eclipse records from ancient Babylon to gauge how fast the Earth’s rotation would be if the planet’s spin were constant, and eliminated factors such as post-glacial rebound and the spinning of the Earth’s core, and found that the planet’s rotation had indeed slowed over the course of the 20th century. But don’t expect to have those extra hours in the day you need to get everything done, as the Earth’s spin now only slows by 1.7 milliseconds each day.