Antarctica’s Melting Ice Shelves Are Dangerous

December 12th, 2020 

by Johnna Crider 

Half of Antarctica’s ice shelves could collapse in a flash, Live Science reports. The article points out that this could result from ongoing global warming.

As meltwater rushes through the cracks in the Antarctic ice shelves, it can destroy the ice shelves in minutes or hours. This is amplified by the warming atmosphere, and as the warming continues, this phenomenon may happen more often than not. A study published back in August showed that at least half of the ice shelves are at risk of having this happening. 

The study suggested that around 50% to 70% of the ice shelves holding Antarctic glaciers in place could become weak and even collapse with surges of meltwater. Ching-Yao Lai, a postdoctoral researcher in the Department of Marine Geology & Geophysics at Columbia University’s Lamont-Doherty Earth Observatory in New York and lead author of the study said, “What we find is that the amount of melting is important, but where the melting happens is also important.”

Christine Dow, the Canada Research Chair in Glacier Hydrology and Ice Dynamics at the University of Waterloo, wasn’t involved with the study but shared her thoughts with Live Science:

“The time frame over which this process could happen is the biggest question.”

“Mass loss from Antarctica (2003–2019). (Top) Mass change for Antarctica. (Bottom) Mass changes at the grounding line. Highest mass loss rates are in West Antarctica and Wilkes Land, East Antarctica. Map and grounding line mass change have been smoothed with a 35 km median filter for improved visualization.” Image courtesy NASA/Science.

Punching Through The Ice

Antarctic ice shelves that are confined to the open water create a barrier that slow-moving glaciers move up against. These buttressing ice shelves were a focal point for the study and they often have cracks on their surfaces as the shelf pushes against the curving shoreline. Also, the shelves stretch out as they flow across the ocean water. “Usually near the front of ice shelves, it gets stretched the fastest and this kind of breaking occurs,” Lai explained.

When the atmosphere is warm, the surface of an ice shelf may start to melt, and when this happens, the meltwater will pool into the cracks and create hydrofracturing, which is a process where excess water puts pressure on the ice. This makes the cracks deeper and can trigger the collapse of that shelf.

Dow explained that the meltwater “can punch through the ice to the ocean in a matter of minutes to hours, as long as there’s enough water available to keep on filling the crevasse and keep up the pressure,” adding that “the crack in the ice then fills up with ocean water.”

This could lead to the shelf breaking apart, which is what scientists believe happened to an ice shelf named Larsen B — it lost 1,255 square miles of ice over a period of a few weeks in 2002.

Lai and her team created a machine learning model to see which buttressing ice shelves were the most vulnerable to collapse. The algorithm can be trained to recognize visual features based on past images it’s analyzed. Lai and her team taught their model to recognize surface fractures in the ice using satellite images of two shelves — Larsen C and George VI — both located in the northwest region of Antarctica. Then they applied the model to a complete map of Antarctica.

After this, the researchers saw which fractures would be at risk of hydrofracture. Dow pointed out that even though researchers had used this analysis at specific ice shelves before, this application is “the first time it has been applied to the Antarctic as a whole.”

The Next Question

The research team is not done asking questions and seeking answers. They wonder, “How does this hydrofracture process contribute to the sea level rise?” To answer this question, her team will pair their model of ice cracks with climate predictions and a model of how ice flows over the bedrock of Antarctica.

Lai pointed out that the research will help the authors see how fast and how much sea-level rise could change due to cracks forming in ice sheets in combination with rising atmospheric temperatures.

The researchers don’t have an exact timeframe yet, but some scientists think that climate change will further accelerate massive hydrofracturing events within a matter of decades.

Final Thoughts

This year has been a really unusual year for many people. We’ve had the global pandemic, Trump and his drama, Black Lives Matter protests (which I support because killings of unarmed black people are abhorrent), the Pentagon released footage of UFOs, a mysterious monolith popping up at random places and then vanishing, and even a former Israeli space security chief saying extraterrestrials exist and claiming that Trump knows about it.

It’s been a helluva year, and so much has happened that the news about Antarctica’s heatwave back in February was probably forgotten. It got up to 64 degrees Fahrenheit, which is pretty much unheard of. And it isn’t stopping there — Antarctica has been simmering for 30 years — much longer than many have realized. The focus of the world is mostly on political games, whether it’s Trump and his drama or other countries with their own issues. Although many nations that took part in the Paris agreement did so because they are concerned with the direction our planet is headed in, I think we have some severe wakeup calls coming as Antarctica’s ice shelves start to collapse. 

As a whole, we are simply not doing enough to stop the heating of our planet. Some are trying, but we all need to get involved, and quite frankly, people who are starving, jobless, and who are trying to survive don’t really care about Antarctica or climate change. There are entire nations that look the other way on issues such as child slavery. There are leaders who are corrupt and don’t care about the wellbeing of their citizens. There are many issues in the world, but ongoing global warming and melting ice shelves will make most of them worse

This mentality has to change, and it starts with all of us.