Global warming is progressing, but probably no one could have expected that an increase in temperature may result in an extension of the day. Such surprising conclusions were reached by scientists who conducted research on the melting of giant ice masses in Greenland and Antarctica.
Research shows that water from melting ice caps in Greenland and Antarctica is causing an increase in mass around the equatorAs Benedikt Soja from ETH Zurich puts it: – It’s as if a figure skater were doing a pirouette, first holding her arms close to her body and then stretching them out. The initially fast rotation becomes slower as the masses move away from the rotation axis, increasing physical inertia.
As the scientists write in their article: “Today’s climate change is unprecedented. In recent decades, the melting of glaciers and polar ice sheets has accelerated, leading to rising sea levels. This mass transport from the pole to the equator has significantly increased the flattening and length of day (LOD) of the Earth since 1900. We show that the current rate of growth is higher than at any time in the 20th century“.
Scientists point out that the Earth is not a perfect sphere, but “bulges” around the equator and “flattens” at the equator. At the same time, over millions of years, its shape changes due to the drift of tectonic plates, catastrophic earthquakes, or great volcanic eruptions.
The research used a unique analysis, i.e. very long baseline interferometry. Thanks to it, it was possible to measure the difference in the time it takes for radio signals from space to reach different points on our planet. This allowed us to obtain the data needed to infer differences in the planet’s orientation and the length of day. In addition, the analyses used the Global Positioning System, which measures the Earth’s rotation to an accuracy of about one hundredth of a millisecond.
Currently, the most important cause of the Earth’s slowdown is the gravitational pull of the moon. The Silver Globe is gradually slowing down (and automatically lengthening the day) by 2.4 milliseconds every century (this has been going on since the creation of this object).
New research suggests that if global warming continues at the same rate, by the end of the 21st century the impact of global warming will be greater than the impact of the moon’s gravity. Since 1900, climate change has lengthened the day by about 0.8 milliseconds. By 2100, climate change will result in the lengthening of the day by 2.2 milliseconds.
It would seem that these are extremely small changes, even insignificant from the human perspective. However, researchers point out that the extension of the day by milliseconds may have many significant complications for navigation on Earth and for future space flights.
The researchers say: “These findings indicate an unprecedented impact of climate change on planet Earth, with implications for precision timekeeping and space navigation“.
Determining the exact orientation of the Earth is crucial communication with spaceshipswhich are located at a very large distance, as for the Voyager probe. In such a case, even a small deviation can result in the signal from Earth missing the probe by tens or even hundreds of kilometers.
The research results were published in a scientific journal Proceedings of the National Academy of Sciences.
Source: geekweek.interia.pl
