Faster Ice Melting Rate In Antarctica Rises Sea Level Than Expected

Pablo Tucker
June 17, 2018

"We now have an unequivocal picture of what's happening in Antarctica", said co-lead author Eric Rignot, a scientist at NASA's Jet propulsion Laboratory who has been tracking Earth's ice sheets for two decades.

"The detailed record shows an acceleration, starting around 2002", said Beata Csatho, one of the study authors and a glaciologist at the State University of NY at Buffalo, in an email. And what we're starting to see are the first signs of some of that ice starting to melt.

The frozen continent lost nearly three trillion tonnes of ice between 1992 and 2017, the 84 scientists said in what they called the most complete overview of Antarctic ice to date. According to a new study, the rapid melting will cause sea levels to rise six inches over the next 80 years.

The Antarctic Ice Sheet covers an area of about 14 million square kilometres; by comparison, the area of Australia is about 7.7 million square kilometres, and that of the United States of America is about 9.8 million square kilometres. The findings helped confirm that the Greenland Ice Sheet is a sensitive responder to global climate change. It holds enough water to cause as much as 34 meters of sea level rise if the ice sheet were to melt completely.

Earlier studies of the East Antarctic Ice Sheet indicated that some marine-based portions of the ice sheet and its neighboring West Antarctic Ice Sheet retreated during the Pliocene.

The melting of Antarctica is accelerating at an alarming rate, with about 3 trillion tons of ice disappearing since 1992, an global team of ice experts said in a new study. As the ice shelves thin and weaken, they provide less resistance to ice flow from the continent to the sea.

"If you're close to the ice sheet that's losing mass you don't really feel the effects as much". Ocean acidification would harm the shells of some sea creatures and the number of invasive species would increase tenfold. It is important, now more than ever, that we continue to use satellites to monitor Antarctica in order to better prepare ourselves for the challenges ahead.

Eric Rignot, from NASA's Jet Propulsion Laboratory, added, "Measurements collected by radar satellites and Landsat over the years have documented glacier changes around Antarctica at an awesome level of precision, so that we have now a very detailed and thorough understanding of the rapid changes in ice flow taking place in Antarctica and how they raise sea level worldwide".

Oceans are now rising by 3.4 millimetres (0.13 inches) per year.

"We can not count on East Antarctica to be the quiet player, and we start to observe change there in some sectors that have potential and they're vulnerable", said Velicogna.

The researchers measured isotopes produced by the interaction between cosmic rays and the nucleus of an atom, called cosmogenic nuclides, in glacial sediment from Antarctic's largest ice shelf.

"There has been a step increase in ice losses from Antarctica during the past decade", said Leeds University professor Andrew Shepherd, co-leader of the Ice Sheet Mass Balance Exercise (ISMBE). This amounts to an additional 15cm in global sea level rise from Antarctica alone by 2100. This week's issue of Nature features several other reports on Antarctica and its future.

"The next piece of the puzzle is to understand the processes driving this change", Durham University's Pippa Whitehouse said.

"What happened roughly 10,000 years ago might not dictate where we're going in our carbon dioxide-enhanced world, where the oceans are rapidly warming in the Polar Regions", said Scherer.

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