Although not designed to map changes in Earth's gravity over time, the earth-orbiting Gravity field and steady-state Ocean Circulation Explorer has shown ice lost from West Antarctica corresponded with a gravity drop.

The strength of gravity at Earth's surface varies subtly from place to place, subject to factors such as the planet's rotation and the position of mountains and ocean trenches, explained a news release from the mission's operator, European Space Agency.

The latest observations from the downward-gazing satellite revealed changes in the mass of large ice sheets can also cause small local variations in gravity.

It was discovered the loss of ice from West Antarctica between 2009 and 2012 caused a dip in the gravity field over the region.

GOCE, more than doubling the time it was designed to function for its initial scientific mission, spent four years measuring Earth's gravity in great detail.

The resulting data have left scientists with the most accurate gravity model ever produced.

As a result, researchers say they now have a much better grasp of many of the planet's natural phenomena, including the boundary between Earth's crust and upper mantle, as well as the density of its upper atmosphere.

High-resolution measurements from GOCE over Antarctica between November 2009 and June 2012 were studied by scientists from the German Geodetic Research Institute, Delft University of Technology in the Netherlands, the Jet Propulsion Lab in Pasadena, California, and the Technical University of Munich in Germany.

Using gravity data to assess changes in the earth's ice mass is not new, as the NASA-German Grace satellite, which was designed to measure such variations, has been providing that very type of observation for over 10 years, said the ESA.

But, measurements from Grace are much less refined than those of GOCE, so they can't be used to look at many of Antarctica's smaller features.

For scientific study, the Antarctic ice sheet is often divided into basins, with some basins much bigger than others.

Comparative measurements can be used to determine how the ice in each basin is changing and discharging ice to the oceans.

By combining GOCE's high-resolution measurements with information from Grace, scientists now have the capacity to examine ice mass changes small glacial systems -- resulting in extraordinary insights into Antarctica's dynamic basin system.

GOCE data also proved helpful in understanding changes of ice sheets and sea levels.

Since 2011, Antarctica as a whole has been shrinking in volume by 125 cubic kilometers a year.

"We are now working in an interdisciplinary team to extend the analysis of GOCE's data to all of Antarctica," said Johannes Bouman from the German Geodetic Research Institute. "This will help us gain ... an even more reliable picture of actual changes in ice mass."