WhatsNew2Day – Latest News And Breaking Headlines
Over the past 25 years, melting Antarctic ice sheets have released a staggering 7.5 trillion tonnes of water into the ocean, a study reveals.
By analyzing more than 100,000 satellite radar images, researchers at the University of Leeds discovered a steady erosion of the continent’s ice sheets, with a reduction of more than 40 percent between 1997 and 2021.
While some ice sheets have increased in size during this time, the data revealed that a third have lost more than 30 percent of their initial mass, releasing large amounts of fresh water in the process.
Worryingly, scientists say this large release of freshwater could threaten to destabilize ocean currents and contribute to global sea level rise.
What’s more, human-induced climate change means ice melting will continue to happen faster in the future, experts warn.
Over the past 25 years, melting Antarctic ice sheets have released a staggering 7.5 trillion tonnes of water into the ocean, a study reveals.
Warmer waters off the west coast of Antarctica have caused the ice sheets to melt at a much faster rate than in the east, where they are protected by a layer of cold water.
Scientists found that while almost all of the East Coast ice sheets were melting, many West Coast ice sheets remained the same size or were growing.
This is due to the patterns of ocean currents that surround Antarctica and transport water of different temperatures.
While the western side is exposed to warm waters that erode the ice shelves from below, East Antarctica is protected by a strip of colder water near the coast.
In total, 59 billion tons of water have been added to the continent’s ice shelves since 1975.
However, this was offset by the 67 billion tonnes that were lost.
The largest losses occurred on the Getz Ice Shelf, which lost 1.9 trillion tons of water.
For perspective, a trillion tons of ice would form a cube more than 10 kilometers (6 miles) in each direction—more than half a mile higher than Mount Everest!
Of this loss, 95 percent was caused by melting and five percent by “calving,” when large chunks of ice break off into the ocean.
Meanwhile, on the other side of Antarctica, the Amery Ice Shelf gained 1.2 trillion tons of ice due to the colder waters around it.
Dr. Benjamin Davison, who led the study, says this evidence points to a distinctive change in Antarctic ice.
“We expected that most ice shelves would go through cycles of rapid, but short-lived contraction, and then slowly grow back,” Dr. Davidson said.
“Instead, we see that almost half of them are shrinking with no signs of recovery.”
Dr. Davidson and his colleagues believe this change is due to human-induced global warming.
If the increased rate of melting was due to natural factors such as a shift in weather patterns, there would also have been evidence of new ice growth in the typically warmer West.
By analyzing more than 100,000 satellite radar images, researchers at the University of Leeds discovered a steady erosion of the continent’s ice sheets, with a reduction of more than 40 percent between 1997 and 2021.
The Getz Ice Shelf, where the worst of the ice melt has occurred, spilled 1.9 trillion tons of water into the Southern Ocean in 25 years.
The team behind this latest study is now concerned that the continued erosion of the ice sheet could have huge knock-on effects on the climate as a whole.
Ice sheets floating in the sea act as giant “plugs” at the end of glaciers.
When glaciers thin or reduce in size, they reach the sea faster, increasing the rate at which ice is lost to the ocean.
If ice shelves are removed or diminished, this may alter the Antarctic ice system as well as global ocean circulation.
In the Southern Ocean, around Antarctica, dense, cold, salty water sinks to the ocean floor.
As water sinks, it forms the engine that drives the giant “conveyor belt,” or ocean currents, that carry nutrients and heat away from the sensitive polar ecosystem.
Since the vast majority of water from melting ice sheets is fresh, this dilutes the salty ocean, making it less dense and taking longer to sink, weakening ocean circulation.
Studies already show that this process could have begun to weaken the delicate balance of the South Pole.
Antarctic sea ice levels are at a “mind-blowing” record low for winter, scientists at the National Snow and Ice Data Center have revealed. The graph shows the current sea ice area compared to the average for this time of year.
Recent research revealed that the ice surrounding Antarctica, known as the sea ice extent, hit a record low in September. measures less than 6.5 million square miles (17 million square kilometers), according to the U.S. National Snow and Ice Data Center.
While this may seem huge, it is actually 580,000 square miles (1.5 million square kilometers) less than the September average, an area equivalent to five times the size of the British Isles.
This comes after scientists revealed that a winter heatwave in March 2022 caused temperatures to rise 40C above normal levels.
If this had happened in summer, scientists say it would have been hot enough to melt the surface of the ice sheets; something that had never been seen before.
Rapid warming has already caused a significant southward shift and contraction in the distribution of Antarctic krill, a keystone species, activists said.
A recent Greenpeace expedition to Antarctica also confirmed that gentoo penguins are breeding further south as a result of the climate crisis.