Scientists crush ice cores to predict Antarctica’s next big ice crack

In Antarctica, two giant rifts, known as Chasm 1 and Halloween Crack, split across the Brunt Ice Shelf. The implications of the cracks are huge as ice shelves hold back huge volumes of landlocked water, regulating its entry into the oceans surrounding Antarctica. But as global warming increases, so too does the likelihood of cracks, calving and the potential collapse of these protective shelves. Events that would have huge ramifications for increased sea level rise. With around 230 million people already living within 1 metre of sea level, the risks are too huge to ignore. That’s why scientists from the British Antarctic Survey (BAS) are studying the cracks to understand how they form and propagate through the ice, with the aim of modelling the events to better predict future rift activity.

The team studies satellite imagery, places seismometers and uses ground-penetrating radar to understand the dynamics of each crack. But it is drilled ice cores that unlock the most useful data, especially when they are subjected to a barrage of tests at a novel lab in London. Part of a unique collaboration between BAS and University College London, the precious Antarctic ice undergoes a series of destructive crush experiments under the watchful eye of earthquake and rock physicist Tom Mitchell. “I’m excited to squash anything you give to me,” he says. The premise, however, is the same: “What controls the strength of material is the things that are within it,” says Mitchell. In this case, it’s the size and orientation of ice crystals. By crushing samples and using high-speed cameras to monitor cracks as they propagate at speeds of up to a kilometre per second, Tom and the team gain valuable insight into fracture toughness. “We are systematically going down through all of the ice,” says Mitchell, “getting the missing pieces of the puzzle to understand what’s quite a complicated, dynamic evolution of the ice shelf over the last 10 years.”

By understanding what happens at the relatively accessible Brunt Ice Shelf, the findings will help scientists better predict what happens across the entire continent, including at the much larger Thwaites glacier – a vast Western Antarctic glacier whose potential collapse could have even larger implications for sea level rise.

Topics:

_{Images are for reference only.Images and contents gathered automatic from google or 3rd party sources.All rights on the images and contents are with their legal original owners.}