Scientists have recorded the shortest day on Earth since the invention of the atomic clock.
Rotation is the time it takes the Earth to rotate once on its axis, which is approximately 84600 sec.
The previous record was documented on July 19, 2020, when the day’s measurement was 1.47 milliseconds shorter than normal.
The atomic clock is a standard unit of measurement that has been used since the 1950s to determine time and measure the Earth’s rotation, said Dennis McCarthy, retired director of time at the US Naval Observatory.
While June 29 broke the record for the shortest day in modern history, there have been much shorter days on Earth, he said.
Why does the speed increase?
McCarthy said the researchers don’t have a definitive answer as to how or why the Earth is rotating a little faster, but it could be due to glacial balance adaptation or the Earth’s movement due to melting glaciers.
He said that the Earth is slightly wider than its height, making it an oblate spheroid. McCarthy said polar glaciers weigh heavily on the Earth’s crust at the north and south poles.
He said that as the poles are melting due to the climate crisis, there is less pressure on the top and bottom of the planet, moving the crust upwards and making the Earth round. The circular shape helps the planet spin faster, McCarthy said.
It’s the same phenomenon that snowboarders use to increase and decrease their speed, he said.