Antarctic glaciers are shedding ice alarmingly faster than previous estimates
We know that Antarctica has been changing in an unprecedented way, losing more ice than ever. However, a NASA-led study based on satellite imagery has found that the ice continent has lost more ice than previous estimates. The study found that the continent has lost 12 trillion tons of ice since 1997. It raises concerns about how climate change is weakening Antarctica's ice shelves.
Why does this story matter?
Antarctica, the only remaining pristine landform on Earth, is also under threat. If you're wondering who's threatening, wonder no more - it's us. The finding that the ice continent has lost double the ice than what we imagined is an alarming one. It's not late though. If we somehow manage to keep things under control, redemption is still a possibility.
Ice lost through calving equal to ice lost from thinning
The study conducted by NASA has found that the edges of Antarctica's ice sheets are losing ice faster than nature can replenish. 'Calving' is the process of breakage of ice chunks from the edge of the glacier. Scientists have found out that Antarctica lost almost the same amount of ice through calving as it lost through the thinning from below by warming seas.
Antarctica lost 12 trillion tones of ice since 1997
In the last 25 years, the net loss for Antarctica from calving alone is nearly 37,000 sq. kilometers. Both calving and thinning have led to the loss of 12 trillion tons of ice since 1997. Thinning leads to an average loss of 149 million tons/year.
Losses from 'calving' is more than natural ice-shelf growth
Using satellite imagery, NASA thoroughly analyzed the edges of ice shelves which equal 50,000 linear kilometers of the Antarctic coastline. Calving is a normal phenomenon when it happens at a steady rate over the long term. According to NASA, losses from calving have outpaced natural ice-shelf growth so greatly. Scientists think that it's impossible for Antarctica to return to pre-2000 levels.
Crumbling ice sheets lead to increase in sea level
Antarctica's ice serves as massive storage facilities for fresh water. When the ice shelves at the edge of the continent fall into the sea as a result of calving, the water held in the sheet trickles into the ocean. These ice shelves hold back glaciers from falling and raising sea levels. Them crumbling would mean a potential spike in sea levels.
Antarctica is crumbling at edges: NASA
The study was led by researchers at NASA's Jet Propulsion Laboratory (JPL). For the study, they used synthesized satellite imagery from visible, infrared, and radar wavelengths. Chad Greene, the study's lead author, said, "Antarctica is crumbling at its edges." "When ice shelves dwindle and weaken, the continent's massive glaciers tend to speed up and increase the rate of global sea level rise," he added.
Calving has also affected the less vulnerable East Antarctic region
The study found out that calving, like thinning, is prominent in the West Antarctica region. However, the phenomenon was also visible in the East Antarctic ice sheet (EAIS). The EAIS holds the majority of the world's glacial ice. If it all melted, the sea level would rise by 52m. Considered less vulnerable until now, the EAIS is also "seeing more losses than gains."
Human activities are at the core of calving and thinning
The cause of the drastic calving and thinning of ice is the rise in temperature. Temperature variations are normal when it happens over time. The current trend of a sudden increase in temperature, however, is due to human activities. This has increased the temperature of the ocean as well. This man-made temperature spike is behind the increase in calving and thinning of ice shelves.