According to satellite data, enough water from melting polar ice caps has flowed onto Earth's equator to make the planet more flattened and less spherical. The best analogy for this phenomenon — this is the execution of such an element in figure skating as centering, when the athlete can slow down the speed of rotation by extending his arms to the sides and accelerate it by pressing his arms to the sides. Thus, the increase in the volume of the planet near the equator slows down the speed of its rotation and actually makes the day longer.
"Enough ice melted to raise sea levels enough that we can actually see how that affected the speed of the Earth's rotation,", — states Duncan Agnew.
It is important that on the scale of billions and millions of years the speed of rotation of the Earth decreased. This was prompted by the gravitational influence of the Moon on the oceans, which created a braking effect. For example, analysis of geological deposits shows that 1.4 billion years ago, a day on Earth lasted 19 hours.
With the advent of the atomic clock in the 60s of the last century, scientists began to notice that the speed of the Earth's rotation is increasing. Since spaceflight, radar, navigation, computers and various electronics began, the change in the speed of the planet had to be somehow correlated with the universal coordinated time based on the atomic clock. Since 1972, a leap second was introduced for this purpose, which made it possible to equalize time and the real daily rotation of the Earth. Everything was fine until the spread of computers and programs, for which an extra second became an incredible headache. It was impossible to take her into account — it was implemented by the command method by authorized organizations.
But the real chaos could come when the negative second was introduced, which was never announced. It was expected that it could be used in 2026. The fact is that the core of the Earth is liquid, and since the 70s, the movement of currents in the core of the planet began to accelerate the rotation of the Earth. This is because the leap second began to be added less often from a certain point. Finally, in 2026, the Earth could overtake the daily readings of the atomic clock, and one second would have to be subtracted from universal time.
Duncan Agnew's work showed that thanks to the melting of the polar ice caps, the speed of the Earth has decreased so much that now the subtraction of one second from universal time can be delayed by three years — by 2029 and in general they will have to be introduced less often. For metrologists, this is a balm for the soul, because no one understands what such a time correction would lead to. For the scientist himself, this is an opportunity to once again show with examples that human activity directly and greatly affects our planet.