‘World’s most dangerous glacier’ could cause catastrophic sea level rise, study warns
- July 10, 2019
A glacier in West Antarctica, known as “the world’s most dangerous,” could totally melt away and cause a quick and “catastrophic” ocean level rise, a new study warns.
The study, published in the scientific journal PNAS, takes note of that the Thwaites Glacier is at a famous “tipping point” that could cause a neverending flow of ice into the world’s oceans.
“If you trigger this instability, you don’t need to continue to force the ice sheet by cranking up temperatures. It will keep going by itself, and that’s the worry,” said the study’s lead author and Georgia Tech professor Alex Robel, in a statement. “Climate variations will still be important after that tipping point because they will determine how fast the ice will move.”
NASA JPL scientist Helene Seroussi, who worked on the study along with Robel, said that the glacier could lose all of its ice over the next 150 years. “That would make for a sea level rise of about half a meter (1.64 feet),” Seroussi added in the statement.
According to the National Oceanic and Atmospheric Administration, sea levels “continue to rise at a rate of about one-eighth of an inch per year.”
The Thwaites Glacier is “the largest single source of uncertainty in projections of future sea-level rise,” according to the study’s abstract. If it were to collapse, it would make “worst-case scenarios of rapid sea-level rise more likely in future projections,” the abstract added.
“If you trigger this instability, you don’t need to continue to force the ice sheet by cranking up temperatures. It will keep going by itself, and that’s the worry.”
The Antarctic ice sheet has more than 50 times the amount of ice than the mountain ice sheets on the world combined, and eight times as much ice in the Greenland ice sheet, Robel added in the statement.
If and when the glacier becomes unstable, the after-effects would be considered “catastrophic.”
“Once [the] ice is past the grounding line and only over water, it’s contributing to sea level because buoyancy is holding it up more than it was before,” Robel said. “Ice flows out into the floating ice shelf and melts or breaks off as icebergs.”
The establishing line is the line between where the ice sheet lays on the ocean bottom and where it extends over the water.
As is normal for most ocean level studies, the time scale for the study was in hundreds of years and reproductions showed that the ice loss for the Thwaites Glacier began following 600 years. In any case, the specialists caution that if sea temperatures keep on rising, the shakiness in the icy mass could happen a lot quicker than many anticipate.
“It could happen in the next 200 to 600 years. It depends on the bedrock topography under the ice, and we don’t know it in great detail yet,” Seroussi added.
Earlier this year, NASA scientists found a massive hole two-thirds the size of Manhattan under the Thwaites Glacier, a fact that left them disturbed.
The huge cavity – which is approximately 1,000 feet tall, about as tall as New York City’s Chrysler Building – is growing at the bottom of the glacier and is large enough to have once contained 14 billion tons of ice, according to NASA. Most of that ice has melted over the past three years.