Scientist claims Earth has shrinking waistline
Published 05 October, 2009, 14:15
Edited 01 November, 2009, 21:30
Our planet is shrinking, says a Russian geologist. Since its early days the Earth’s average radius has reduced by 585 kilometers.
Vyacheslav Orlenok, professor of geology at the Kant Russian State University in Kaliningrad, compared ancient relief structures to those of today, he reports in a paper.
He says 4.5 billion years ago, when Earth’s surface had just started to solidify, the little blue ball was a bit bigger. Its average radius was 6,956 km, and has since reduced by 585 km.
Over the eons this resulted in the reduction of its surface by 128 million square kilometers, as compared to the total area of all the continents today of about 149 million square kilometers. The shrinking is a major factor in tectonic processes such as the movement of continental platforms, Orlenok says.
The reduction in size was due to gravitational forces and the loss of mass caused by the Sun’s radiation blowing away hydrogen atoms from the Earth’s atmosphere, explains the scientist, who has been studying the formation of Earth’s oceans and crust for more than 30 years.
The theory of a shrinking earth is contestable, commented Vladimir Shevchenko, a geologist at the Institute of Earth Physics, who spoke to Moskovsky Komsomolets newspaper.
“Now it’s impossible to make an exact calculation of the ancient Earth’s radius based on ancient structures,” he said, adding that alternative theories of an expanding or “pulsating" Earth also exist.
Back in 2007, researchers at the University of Bonn in Germany reported that Earth’s radius was 2.5 millimeters smaller than geologists previously though. However it was not due to shrinking, but rather a more accurate measurement technique used by the team.
discuss it Show comments (4)
