The universal time indication (UTC) is based on the speed at which the Earth rotates on its axis and atomic clocks. Because the speed of the Earth’s rotation is not constant, so-called ‘leap seconds’ had to be added regularly to bring the two back into balance.
However, the Earth is now starting to spin faster and faster on its axis, so it looks like a second will have to be subtracted, which has never happened before.
Melting ice caps
However, it now appears that the melting of the ice caps is a limiting factor. The meltwater moves from the poles towards the equator, causing the Earth to become slightly wider at that location and thus slowing down its speed somewhat.
The melting of the ice caps “has been large enough to noticeably affect the rotation of the entire Earth,” Duncan Agnew, professor of geophysics at the University of California – San Diego and author of the study told CNN. “The fact that humans have influenced the rotation of the Earth is astonishing.”
As a result, the leap second would only have to be subtracted in 2029, while it previously looked like this would already be the case in 2026.
If that happens, many computers will have to be reprogrammed. “No one ever anticipated that the Earth would accelerate so that we would have to subtract a leap second,” Agnew said.
Tags: Melting ice caps ensure Earth rotates quickly axis impact time measurement
