There's a tell-tale wobble as the Earth spins on its axis that has caught scientists' eyes for years — and now they know what's causing it.
As with many of the strange, abnormal phenomena in the planet, the uneven spin can be traced back to climate change.
The Earth's Odd Wobble
According to Live Science, scientists have noted subtle shifts in the Earth's spin as far back as thousands of years ago. As technology developed, measurements reveal that the axis of rotation drifts toward the Hudson Bay in Canada by a few centimeters every year. All in all, the planet has shifted roughly 34 feet since 1899.
A fraction of the wobbling is known to be due to glacial isostatic adjustment, which is when glaciers retreat and relieve the underground land of mass. As a response, the land rises like bread dough.
However, in a study published in the journal Earth and Planetary Science Letters, researchers reveal that human impact on the environment is the main driver behind the planet's wobble.
As a whole, environmental processes cause 1.7 inches of wobble every year. The melting of the Greenland ice sheet was particularly momentous as it involved a large mass of previously locked in water to be redistributed. It was enough, scientists say, to have a notable effect on the planet's rotation.
Finally, a third of the wobble was accounted for when the scientists took a peek inside the Earth. Here, the mantle is constantly in motion with the process of convection. The activity, when the hot material rises and the cooler material sinks, creates a cycle of motion that contributes to the shifting spin of the planet.
What The Wobble Means For Earth
The authors assure that the Earth's wobble is not expected to cause adverse consequences or calamities on agriculture, climate, or the environment. Even any effect on navigational equipment could be easily amended.
Surendra Adhikari, lead researcher of the study and an Earth system scientist at NASA's Jet Propulsion Laboratory, explains that the regular drift that occurs in the Earth's spin is not a large amount.
The findings of their study remain significant, though, especially for those who are analyzing the planet's mass and how it is affecting the environment.
"That fact is important for climate scientists because they can understand, in a global sense, which are the most important mass transports that are going on today," Erik Ivins, coauthor of the study and a senior research scientist at NASA's Jet Propulsion Laboratory, explains.