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Worrying: Scientists Say a Quarter of Antarctica is now Unstable

According to reports from the University of Leeds, in only 25 years, the melting of our oceans has caused ice thinning to spread across West Antarctica so rapidly that as much as 24% of its glacier ice is now affected.

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Since 1992, the loss of ice has spread to 24% of West Antarctica and its largest glaciers, such as Pine Island and Thwaites, which were found to be losing ice five times as faster than they were at the start of the study.

According to a new study which combines 25 years of European Space Agency satellite altimeter measurements and a model of the regional climate, a quarter of West Antarctic ice is highly unstable.

This was found by a team of researchers, led by Professor Andy Shepherd of the University of Leeds, which discovered that the Antarctic ice sheet had thinned to a worrying 122 meters in certain areas with the fastest changes identified in West Antarctica, where ocean melting has caused an imbalance in glaciers.

In other words, the glaciers in question are unstable as they are losing even more mass thanks to melting and iceberg calving than the are gaining it through snowfall.

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The study, published in the journal  Geophysical Research Letters, made use of more than 800 million measurements of the Antarctic ice sheet height recorded by the ERS-1, ERS-2, Envisat, and CryoSat-2 satellite altimeter missions between 1992 and 2017 and simulations of snowfall over the same period produced by the RACMO regional climate model, explain researchers in a statement.

This animated image show s a time sequence of Antarctic glacier ice thickness change (left) and associated contribution to sea level rise (right) between 1992 and 2017. Image Credit: University of Leeds.
This animated image show s a time sequence of Antarctic glacier ice thickness change (left) and the associated contribution to sea level rise (right) between 1992 and 2017. Image Credit: University of Leeds.

These measurements have allowed experts to separate the changes in the height of the ice sheet into those that are caused by weather patterns, such as less snowfall, and longer-term changes in climate, such as the increase in ocean temperatures that cause the ice to melt faster.

“In parts of Antarctica, the ice sheet has thinned by extraordinary amounts, and so we set out to show how much was due to changes in climate and how much was due to weather,” professor Andrew Shepherd revealed.

Scientists compared the measured surface height changes to the simulated changes in snowfall.

Where they identified a greater difference, they attributed its origin to glacier imbalance.

Scientists discovered that fluctuations in snowfall usually drive small changes in height over larger areas for a few years at a time. However, they discovered that the greatest changes in ice thickness are clear signs of glacier imbalance that have lasted for decades.

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Shutterstock.

“Knowing how much snow has fallen has really helped us to detect the underlying change in glacier ice within the satellite record. We can see clearly now that a wave of thinning has spread rapidly across some of Antarctica’s most vulnerable glaciers, and their losses are driving up sea levels around the planet,” Sheppard added.

“Altogether, ice losses from East and West Antarctica have contributed 4.6 mm to global sea level rise since 1992,” the researcher added.

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All of this is evidence of the importance of satellite data, and how information gathered from space can help us better understand our planet.

This is an important demonstration of how satellite missions can help us to understand how our planet is changing.

“The polar regions are hostile environments and are extremely difficult to access from the ground. Because of this, the view from space is an essential tool for tracking the effects of climate change,” concluded co-author of the study, Dr. Marcus Engdahl of the European Space Agency.

Source
University of Leeds