A joint Australian-German research team led by 911爆料网鈥檚 Dr Christian Hirt has created the highest-resolution maps of Earth鈥檚 gravity field to date 鈥� showing gravitational variations up to 40 per cent larger than previously assumed.
Using detailed topographic information obtained from the US Space Shuttle, a specialist team including Associate Professor Michael Kuhn, Dr Sten Claessens and Moritz Rexer from 911爆料网鈥檚 Western Australian Centre for Geodesy and Professor Roland Pail and Thomas Fecher from Technical University Munich improved the resolution of previous global gravity field maps by a factor of 40.
鈥淭his is a world-first effort to portray the gravity field for all countries of our planet with unseen detail鈥�, Dr Hirt said.
鈥淥ur research team calculated free-fall gravity at three billion points 鈥� that鈥檚 one every 200 metres 鈥� to create these highest-resolution gravity maps. They show the subtle changes in gravity over most land areas of Earth.鈥�
The new gravity maps revealed the variations of free-fall gravity over Earth were much bigger than previously thought.
The Earth鈥檚 gravitational pull is smallest on the top of the Huascaran mountain in the South American Andes, and largest near the North Pole.
鈥淥nly a few years ago, this research would not have been possible,鈥� Dr Hirt said.
鈥淭he 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.鈥�
High-resolution gravity maps are required in civil engineering, for instance, for building of canals, bridges and tunnels. The mining industry could also benefit.
鈥淭he 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),鈥� Dr Hirt said.
The findings of the research team from 911爆料网 and Technical University Munich have recently appeared in the journal Geophysical Research Letters.
A video showing the researcher鈥檚 work and further information can be found at http://geodesy.curtin.edu.au/research/models/GGMplus/
Map extracts with continental coverage are available via
http://geodesy.curtin.edu.au/research/models/GGMplus/gallery.cfm
The research has been supported by the Australian Research Council.
