Researchers have found that the Wilkes Subglacial Basin's base, which consists of enough ice to raise sea levels by up to 10 feet, could be close to thawing.
Wilkes Subglacial Basin
The Wilkes Subglacial Basin, which has the size of California and is situated in East Antarctica, is a down-sloping and broad basin that stretches 1,400 kilometers inland and has ice with a thickness of three kilometers. It empties into the Southern Ocean through some glaciers and ice shelves. Its ice sheet is situated below sea level, right at the bottom. Hence, its glaciers' undersides are susceptible to melting from warming seawater inflows.
Previously, the massive sheet was believed to be stable. However, it appears to be nearing a runaway melt.
Such a discovery was made by researchers with the help of radar surveys from planes that were flying over the sheet to examine the ice below. If small increases in temperature keep building up under the sheet, its front edge could end up becoming unstuck and eventually collapsing. Findings were noted in the new study, "Heterogeneous Basal Thermal Conditions Underpinning the Adélie-George V Coast, East Antarctica."
Eliza Dawson, a geophysics doctoral student from Stanford University, shares that not much analysis has been done in the region. While a massive volume of ice is situated there, it has remained relatively stable. Dawson shares that, for the first time, they are examining temperatures at the ice sheet's base and seeing how close it is to possibly melting.
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Potentially Melting
For a long time, scientists have assumed that the ice in East Antarctica is quite stable. Rather than focusing on this, they paid attention to the gravely calving glaciers of West Antarctica.
However, a new study has suggested that the East Antarctic Ice Sheet went through grave melting and retreat in earlier periods of warming. This raises the probability of awakening the giant in slumber.
Dustin Schroeder, a co-author of the study and an associate geophysics professor from Stanford University, explains that imaginable conditions are present in the area. Schroeder notes that if warm water goes there, it will switch on a full Antarctic sector that is not normally thought to contribute to rising sea levels.
To examine what was happening under the sheet, the researchers gathered data through the radar surveys. Given the higher reflectiveness of water compared to bedrock, the radio waves that are fired at the beds under the ice sheets get reflected more compared to those that have stayed frozen.
By examining the reflected radio signal tangles before comparing them with some that were taken on land, the scientists could weave them to be part of a map of the melt through thousands of miles of the southern coastline of the basin.
The researchers observed something that was alarming. They found that there were huge patches of frozen and thawed ground beneath the ice sheet. However, the majority of the area could not fit into either category.
This may suggest that there could have been some shifts in the geometry of the ice sheet or that the data has complications. It may also indicate that most of the ground under the sheet could be semi thawed. This could mean that it is potentially moving close to a tipping point if the temperatures of the ice sheet's base keep going up.
Dawson explains that this suggests the possibility of a future glacial retreat, stressing the need to understand how it may evolve and turn unstable.
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