Researchers have created the highest-resolution maps of the Earth's gravity field yet, revealing in the process gravitational variations up to 40 percent larger than previously assumed.
Conducted by a joint Australian-German research team, the study used detailed topographic information obtained by the US Space Shuttle in order to improve the resolution of previous global gravity field maps by a factor of 40. In doing so, they discovered far larger variations in free-fall gravity over Earth than previous estimates proposed.
According to the maps, the Earth's gravitational pull is smallest on the top of the Huascaran mountain in the South American Andes. The largest pull, meanwhile, is found near the North Pole.
"This is a world-first effort to portray the gravity field for all countries of our planet with unseen detail," study lead Christian Hirt of Curtin University said in a statement, adding that just a few years ago, the study would have been impossible.
"The creation of the maps would have required about 80 years of office PC computation time but advanced supercomputing provided by the Western Australian iVEC facility helped us to complete the maps within a few months," he explained.
Gravity maps serve a variety of purposes. They are required, for example by civil engineers looking to build anything from canals to bridges and tunnels. Furthermore, the mining industry stands to gain from knowing just how strong gravity's pull is in a given area compared to other locations.
"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 (GPS)," Hirt said.
Other researchers included Michael Kuhn, Sten Claessens and Motiz Rexer from Curtin's Western Australian Center for Geodesy as well as Roland Pail and Thomas Fecher from Technical University Munich. The findings are published in the journal Geophysical Research Letters.