The prospect for doomsday glacier retreat in Antarctica

A new seabed map suggests that the ‘Doomsday Glacier’ is significantly closer to disaster than experts previously anticipated.

According to researchers, the ice mass is “hanging on by its fingernails.”

Underwater robots looking beneath Antarctica’s Thwaites Glacier, dubbed the “Doomsday Glacier,” discovered that its demise may occur sooner than projected due to an unprecedented rise in ice loss. A comprehensive picture of the seafloor surrounding the icy giant has revealed that the glacier has had phases of fast retreat in recent millennia, which might be triggered again by melt caused by climate change.

Thwaites Glacier is a large block of ice — roughly the size of Florida in the United States or the entire United Kingdom — that is slowly melting into the ocean off West Antarctica. The glacier’s gloomy name comes from the “spine-chilling” consequences of its entire liquidation, which may raise global sea levels by 3 to 10 feet (0.9 to 3 metres), according to experts. According to the International Thwaites Glacier Collaboration, the massive frozen mass is retreating twice as quickly as it was 30 years ago as a result of climate change, and it is losing roughly 50 billion tonnes (45 billion metric tonnes) of ice yearly.

The Thwaites Glacier is kept in place by steep cliffs on the seafloor that restrict the glacier’s fall into the water. Grounding points are sections of seabed that grasp hold of a glacier’s underbelly and play an important role in how rapidly a glacier may retreat.

An international team of researchers employed an underwater robot to map out one of Thwaites’ previous grounding points: a jutting seabed ridge known as “the bump,” which is approximately 2,133 feet (650 m) below the surface. The resultant map shows that when the hump was holding up Thwaites Glacier over the previous two millennia, the glacier’s ice mass fell more than twice as rapidly as it does now.

The new map, according to the researchers, is a “crystal ball” that shows what can happen to the glacier in the future if it becomes divorced from its present grounding point — which is roughly 984 feet (300 m) below the surface — and becomes anchored to a deeper one, such as the bump. According to the statement, this situation may become more likely in the future as increasingly warm waters melt away the glacier’s innards.

“Thwaites is truly hanging on by its fingernails today,” research co-author and British Antarctic Survey marine geophysicist Robert Larter said in a statement. “In the future, we should expect to witness large changes on tiny periods.”