Antarctic Ice Melt is Changing Earth’s Gravity – D-brief |

A new study may help mankind understand the gravity of climate change.

West Antarctica has lost so much ice between 2009 and 2012 that the gravity field over the region dipped, according to an announcement Friday from the European Space Agency (ESA). The conclusion is based on high-resolution measurements from satellites that map Earth’s gravity.

The gravitational fluctuation over the Antarctic Peninsula is small, but it’s further evidence that melting ice is fundamentally changing parts of the planet.

Measuring Earth’s Gravity

Scientists combined measurements from the ESA’s GOCE satellite and the lower-resolution Grace satellite, which is operated by the United States and Germany. Both satellites take detailed measurements of Earth’s gravity field and how the planet’s mass is distributed. Data from these instruments help scientists better understand the structure of Earth’s interior and its atmosphere.

Earth’s gravity field fluctuates from place to place depending on the planet’s rotation and the presence of mountains or ocean trenches.

Based on measurements from these two satellites, West Antarctica’s gravitational pull measurably decreased over three years because of its lost mass. Although you won’t feel a difference in the planet under your feet, the findings are further proof that, yes, ice is melting in Antarctica.

Corroborating Evidence

The findings from GOCE and Grace gel with data from a separate mission, ESA’s CryoSat satellite, which carries a radar altimeter (a device that uses radio waves to map the terrain’s altitude). It found that the rate at which ice is lost on the West Antarctic Ice Sheet has increased by a factor of three since 2009. The frozen continent has been shrinking by 77 square miles every year, according to CryoSat data.

The news doesn’t get much better for Antarctica. Earlier this year, two studies were released that indicated the West Antarctic Ice Sheet is headed for an irreversible collapse in roughly 200 years. Should the ice sheet completely collapse, scientists believe it could raise sea level by more than 10 feet.


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