Antonio Manaytay – Fourth Estate Contributor
Austin, TX, United States (4E) – A new study has warned that the East Antarctic Ice Sheet may no longer be as stable as previously thought it was. The ice sheet in the region with its long history of expanding and shrinking due to climate change has the potential to raise the global sea level from 3 to 5 meters. In a study published on December 14 in the journal Nature, the researchers said the region is likely to be susceptible to climate change because they flow from the Aurora Basin, East Antarctica’s region that lies mostly below sea level. The study led by The University of Texas Austin and the University of South Florida had collected geophysical and geological data from the first oceanographic survey of East Antarctica’s Sabrina Coast. It was found out that the glaciers in the Aurora Basin were stable only for the last few million years, study co-lead author Sean Gulick, a research professor at the University of Texas Institute for Geophysics (UTIG) and the Department of Geological Sciences, said. “It turns out that for much of the East Antarctic Ice Sheet’s history it was not the commonly perceived large stable ice sheet with only minor changes in size over millions of years,” he said. Recent data collected from the region, Gulick said, had indicated that the ice sheet is dynamic as it “grew and shrank significantly between glacial and interglacial periods.” “There were also often long intervals of open water along the Sabrina Coast with limited glacial influence,” he added. The researchers were able to determine how the ice sheet in the region had grown and shrunk for the past 50 million years with the help of marine seismic technology. Samples of mud taken from 1 to 2 meters below the seafloor helped to determine the age of the samples. The data revealed that the ice sheet had advanced from the Aurora Basin and shrank again 11 times the last 20 million years. The young ice sheet, according to researchers, was wetter than it is today with a network of channels underneath where the melted ice flows. “We shouldn’t view this as one ice sheet that suddenly grew to its present size, but rather one that was a transient ice sheet that expanded every couple million years or so,” Gulick said. The East Antarctic Ice Sheet had stabilized about six million years ago but the increasing global air temperatures due to climate change may cause the melting of the glaciers in the region. At present, the glaciers in the Sabrina Coast and that of the Aurora Basin are thinning due to the warming of ocean waters nearby. Study co-lead author Amelia Shevenell said the melting of Toten Glacier, East Antarctica’s largest glacier as an early warning sign of the impending instability of ice sheet in the region. Shevenell is an associate professor in the University of South Florida’s College of Marine Science. “A lot of what we are seeing right now in the coastal regions is that warming ocean waters are melting Antarctica’s glaciers and ice shelves, but this process may just be the beginning,” she said. “Once you have that combination of ocean heat and atmospheric heat – which are related – that’s when the ice sheet could really experience dramatic ice mass loss,” Shevenell said.
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