Antarctica is dominated by ice, mainly two massive ice sheets called the East Antarctic and West Antarctic ice sheets. Not surprisingly, these ice sheets have been losing mass in recent years. Two glaciers within these ice sheets, the Thwaites and Pine Island glaciers, are under particular threat. At current rates of melt, scientists estimate that these ice sheets together will cause sea levels to rise by 3.4 meters in the coming centuries.
A new study by the University of Maine and the British Antarctic Survey has measured the rate of sea level change in the Antarctic region. The study reveals something troubling. Glaciers are retreating at a rate not seen in 5,500 years. The Thwaites and Pine Island glaciers lost 192,000 square kilometers and 162,300 square kilometers, respectively. Only these glaciers can significantly increase global sea level rise.
“We found that while these vulnerable glaciers have been relatively stable over the past few millennia, their current rate of retreat is accelerating and already raising global sea levels,” said study co-author Dr Dylan Rude, an expert in the Department of Geosciences and Engineering at Imperial College London.
These increased rates of ice melt may indicate that vital arteries in the heart of the West Antarctic Ice Sheet have been ruptured, resulting in an accelerated flow into the ocean that is potentially catastrophic for future global sea levels in a warming world.” Is it too late to stop bleeding?”.
In the middle of the Holocene, more than 5,000 years ago, the climate on Earth was much warmer than it is today. Because of the warmer climate, scientists wanted to look at sea levels to compare it to what our future might be. To study sea levels, the researchers studied sea-shells and penguin bones, indicators of sea levels. Using carbon dating, they were able to determine the time frame of these remains.
Interestingly, the sea level in Antarctica during the warmer period was lower than in the whole world, and at the same time higher. This is because the weight of glacial ice presses on land, causing it to sink lower into the water and rise higher when the ice melts, relieving the pressure. Overall, researchers have been able to see sea levels drop in Antarctica as glaciers melt, but sea levels rise almost everywhere. To better understand this phenomenon and possibly find possible solutions, scientists plan to conduct additional studies.
The study is published in the journal Nature Geoscience.