Less than a week after the news broke that Antarctica’s largest iceberg may be doomed to disappear forever, as reported by the Inquisitr, two separate studies published on June 13 in the journal Nature explore what’s been happening to the Antarctic Ice Sheet and how the rapid ice loss of the recent years can affect Antarctica’s ice shelves.
According to one of the studies, Antarctica’s ice sheets are melting faster than previously imagined, disappearing at a rate three times more rapid than a decade ago, the Smithsonian Magazine reports.
Conducted as part of the Ice Sheet Mass Balance Inter-Comparison Exercise (IMBIE), a scientific collaboration between NASA and the European Space Agency, the research investigated the mass balance of the Antarctic Ice Sheet from 1992 until 2017 and uncovered that the loss of Antarctic ice has tripled its rate over the last decade.
The scientists revealed that in 2007, Antarctica was losing ice at a rate of 73 billion metric tons per year, which accelerated over the last 10 years to a staggering 219 billion tons per year.
Antarctica’s ice sheets hold 60 to 90 percent of the planet’s fresh water. The current fast pace at which this ice is melting is estimated to trigger a six-inch rise (15 centimeters) in global sea levels by the end of the century.
“The Antarctic Ice Sheet is an important indicator of climate change and driver of sea-level rise,” the IMBIE team wrote in their Nature paper.
As lead author Andrew Shepherd of the University of Leeds in the U.K. told the New York Times, this six-inch rise in the world’s sea levels would translate into a dramatic increase of floods in the Brooklyn borough of New York City.
“Around Brooklyn you get flooding once a year or so, but if you raise sea level by 15 centimeters then that’s going to happen 20 times a year,” said Shepherd.
More than 3.3 trillion tons of ice have already melted away since 1992, contributing to a quarter-inch rise (7.6 millimeters) in global sea levels — 40 percent of which (or a 3-millimeter rise) taking place during the last five years, notes Eurek Alert.
The massive ice loss recorded since 1992 is largely attributed to the thawing of the West Antarctic Ice Sheet and the Antarctic Peninsula, shows a report by Axios.
The biggest concern is West Antarctica, which has lost 159 billion tons of ice a year between 2012 and 2017 — more than double the melting rate recorded between 2002 and 2007, which led to an annual loss of 65 billion tons of ice.
The region’s largest glaciers, Pine Island and Thwaites — which is considered the most dangerous glacier in the world and will be studied intensively over the next three years, the Inquisitr reported in April — “hold the unwelcome distinction of having the world’s highest annual levels of glacier loss,” notes the Smithsonian Magazine.
One of the effects of the unprecedented ice loss is that it produces ocean swells, creating powerful waves that chip away at the Antarctic ice shelves and can cause them to collapse, Science Daily reports.
The video below, a time-lapse footage provided by the Australian Antarctic Division (AAD) in Tasmania, reveals the impact of large ocean waves as they batter the Antarctic ice shelf, triggering the collapse of a significant, previously weakened area which had already experienced fracturing.
Dr. Rob Massom, a researcher at the AAD and the lead author of a Nature study on the disintegration of the Antarctic Ice Shelf, explains the process.
“Sea ice acts as a protective buffer to ice shelves, by dampening destructive ocean swells before they reach the ice shelf edge. But where there is loss of sea ice, storm-generated ocean swells can easily reach the exposed ice shelf, causing the first few kilometers of its outer margin to flex.”
In time, this flexing weakens the cracks and fractures already existing in Antarctica’s ice shelves, causing them to break up and splinter, calving off in detached pieces.
“Understanding the causes of recent catastrophic ice shelf disintegrations is a crucial step towards improving coupled models of the Antarctic Ice Sheet and predicting its future state and contribution to sea-level rise,” the authors write in their paper.
Their research documented the disintegration events recorded during the collapse of the Larsen A Ice Shelf in 1995, which resulted in the rapid loss of 1,600 square kilometers of ice, as well as the 2002 collapse of the Larsen B Ice Shelf (3,320 square kilometers of lost ice) and the 2009 the Wilkins Ice Shelf collapse (1,450 square kilometers of lost ice).
When the Larsen B Ice Shelf came tumbling down 16 years ago, it dislodged a piece of ancient ice that had been floating steadily for 11,500 years, only to get torn apart in a just a few days, reveals Science Daily.