And Antarctica isn't the only contributor to sea level rise - a recent study found that our oceans are warming at a faster rate than expected due to climate change, and warmer waters mean rising seas.
"As climate warming and ozone depletion send more ocean heat toward [the sectors of Antarctica losing the most ice], they will continue to contribute to sea level rise from Antarctica in decades to come", Rignot said.
Overall, the scientists said that the melt of Antarctica added water equivalent to 13.2 millimetres (0.5 inch) of sea level rise over the past four decades.
It takes 360 billion tons of ice to produce one millimetre of global sea-level rise.
The pace of melting also increased from 1979 to 2017: Antarctica's ice melting pace was an average of 48 gigatons per year, per decade.
However, a subsequent study published in Nature in September 2018 analysed layers of sediment from the ocean floor deposited the last time the Wilkes Subglacial Basin, part of the Eastern Antarctic due south of Australia, melted around 125,000 years ago.
"What this study does is characterize the growth and decay of the Antarctic ice sheet and sheds light on what is forcing it to change", explains Meyers.
Already, Antarctic melting has raised global sea levels more than half an inch (1.4 centimetres) between 1979 and 2017, said the report in the Proceedings of the National Academy of Sciences (PNAS), a peer-reviewed U.S. journal.
The outward ice flow is normal and natural, and it is typically offset by some 2 trillion tons of snowfall atop Antarctica each year, a process that on its own would leave Earth's sea level relatively unchanged.
Antarctica contains 90% of the world's glacier ice - enough ice to raise world sea level by over 60 meters (almost 200 feet) if it were all to melt.
People are being urged to play their part in saving the Antarctic as a new study paints an alarming picture of the threat global warming poses to the frozen continent.
"The places undergoing changes in Antarctica are not limited to just a couple places", Rignot told the Washington Post. However, in the period from 2009 to 2017, this figure jumped to 252 billion tons.
That kind of sea-level rise would result in the inundation of island communities around the globe, devastating wildlife habitats and threatening drinking-water supplies. "They seem to be more extensive than what we thought".
A landmark study published in Nature in June a year ago found that Antarctic ice melt had tripled since 1992, but did not show significant melting in the east.
Another troublesome finding in the study was the fact that East Antarctica has also been losing ice significantly over the same time period. The ice shelves act as an ocean-facing, protective barrier, keeping land-ice locked in place. In the Antarctic, the ice shelves extend from the land out over the water.