Earth's Gravity Variations 40 Percent Larger Than Scientists Thought

Earth's gravity field may be a bit bigger than we thought. Using the highest-resolution maps of Earth's gravity field to date, scientists have discovered gravitational variations of up to 40 percent larger than previously assumed.

Actually creating these maps wasn't easy, though. The researchers had to use detailed topographic information obtained from the U.S. Space Shuttle. This allowed them to improve the resolution of previous global gravity field maps by a factor of 40.

"This is a world-first effort to portray the gravity field for all countries of our planet with unseen detail," said Christian Hirt, the team leader, in a news release. "Our research team calculated free-fall gravity at three billion points--that's one every 200 meters--to create these highest-resolution gravity maps. They show the subtle changes in gravity over most land areas of Earth."

Earth's gravitational pull is smallest on top of the Huascaran mountain in the South American Andes and the largest near the North Pole. The new maps, though, reveal variations of free-fall gravity over Earth that are much larger than previously thought.

So what can these new maps be used for? High-resolution gravity maps are required in civil engineering for building canals, bridges and tunnels. The maps can also be utilized by the mining industry.

"The maps can be used by surveyors and other spatial science professionals to precisely measure topographic heights with satellite systems such as the Global Positioning System," said Hirt in a news release.

This particular feat of map creation wouldn't have been possible several years ago. In fact, their creation would have required about 80 years of office PC computation time. Yet with supercomputing on the rise, the maps were created in only a few months.

Want to see the Earth's gravitational field for yourself? You can check it out in the gallery here.