Sudden ice loss in Antarctica affects Earth's gravity field

A sudden increase in ice loss in a previously stable region of Antarctica is causing small changes in the gravity field of the Earth, says a team of scientists.

Around 2009, multiple glaciers along a vast coastal expanse, measuring some 750 km in length, suddenly started to shed ice into the ocean.

"To date, the glaciers added roughly 300 cubic km of water to the ocean. That's the equivalent of the volume of nearly 350,000 Empire State buildings combined," said lead study author Bert Wouters at the University of Bristol.

The changes were observed using the CryoSat-2 satellite, a mission of the European Space Agency dedicated to remote-sensing of ice.

The ice loss in the region is so large that it is causing small changes in the gravity field of the Earth. Such a change can be detected by another satellite mission, the Gravity Recovery and Climate Experiment (GRACE).

Ice shelves in the region have lost almost one-fifth of their thickness in the last two decades, thereby reducing the resisting force on the glaciers.

"To pinpoint the cause of the changes, more data need to be collected. A detailed knowledge of the geometry of the local ice shelves, the ocean floor topography, ice sheet thickness and glacier flow speeds are crucial to tell how much longer the thinning will continue," Wouters concluded.

The research was published in the journal Science.