Researchers recently discovered that the fast-melting Antarctic Denman glacier, melting due to climate change, could release billions of tons of ice, enough to raise global sea levels by nearly 5 feet,media reported. Scientists tracking global warming had thought there was a lower risk of melting glaciers in East Antarctica, but new findings published this week suggest that is not the case.
Rising temperatures have caused glaciers to melt and release ice water into the sea, a topic of concern for scientists. Although some degree of melting and refreezing is expected as the region experiences a natural cycle, a steady recovery in temperature levels has changed the balance and caused the melting of glaciers to melt much faster than previously predicted.
Now a new study of the Denman Glacier in East Antarctica suggests the problem may be more serious than scientists fear. Looking back over the past 22 years, researchers at the University of California, Irvine, and NASA’s Jet Propulsion Laboratory have found signs of potential instability in the ocean ice sheet. Between 1979 and 2017, the glacier is believed to have lost a total of 268 billion tons of ice.
Melting glaciers isn’t just about temperature.
What exacerbates this problem is the shape of the glacier itself and the land it is in. The researchers found that while the eastern side of the ice was effectively protected by the sub-ice ridge to prevent it from retreating, the western side did not meet this need well. Instead, it warns, it has a deep and steep trough, especially for accelerated ablation.
“Due to the shape of the ground below the west side of the Denman Glacier, rapid and irreversible melting is possible, which means that global sea levels will rise significantly in the future,” explained lead author Virginia Brancato. Brancato is a postdoctoral fellow at NASA JPL. The paper was published this week in the journal Geophysical Research Letters.
In just over two decades, the glacier has retreated for nearly three miles. But if it were to melt completely, the Denman Glacier would have a greater impact on the sea. Scientists estimate that melting glaciers could cause global sea levels to rise by about 1.5 meters (about 5 feet).
Monitoring glacier melting from space
Not every part of the glacier is at the same risk of melting. Of particular concern is the floating extension of about 9,300 square miles, including the Denman ice tongue and the Shackleton ice shelf.
Data from the TanDEM-X satellite of the German Aerospace Centre and the Cosmo-SkyMed satellite system in Italy can be used to monitor the impact on these areas. For example, the ice tongue sheds about 10 feet of mass each year. This is above average compared to other ice shelves in East Antarctica.
Earlier this month, NASA warned that the Greenland and Antarctic ice sheets were melting six times faster than they did in the 1990s. It is well known that climate change and melting glaciers are destroying major ocean currents.