According to new research, Antarctica’s “Doomsday Glacier,” so named because its collapse could cause catastrophic sea level rise, is melting swiftly and in unexpected ways.
Thwaites Glacier is located in West Antarctica and is nearly the size of Florida. An ice shelf that juts out into the ocean’s surface helps to keep it in place. The shelf functions like a cork, keeping the glacier on land and providing a crucial barrier to sea level rise.
However, the critical ice shelf is becoming increasingly fragile as the water warms.
Scientists revealed in two research published on Wednesday in the journal Nature that while the rate of melting beneath much of the ice shelf is slower than previously thought, deep fissures and “staircase” structures in the ice are melting much faster.
The Thwaites Glacier is changing rapidly as climate change intensifies.
Every year, it releases billions of tonnes of ice into the ocean, accounting for around 4% of yearly sea level increase. Rapid melting occurs at the glacier’s meeting point with the seafloor, which has receded roughly nine miles (14 kilometres) since the late 1990s, exposing a wider slice of ice to comparatively warm ocean water.
The total collapse of the Thwaites might result in a sea level rise of more than two feet (70 centimetres), devastating coastal cities around the world. However, the Thwaites is also acting as a natural dam to the surrounding ice in West Antarctica, and experts estimate that if the Thwaites collapsed, global sea level would rise by roughly 10 feet.
While it could take hundreds or thousands of years, the ice shelf could dissolve considerably sooner, causing the glacier to retreat in an unstable and potentially irreversible manner.
In late 2019, a team of US and British scientists from the International Thwaites Glacier Collaboration travelled to the glacier to better understand the altering of the isolated coastline.
They dug a hole about 2,000 feet (600 metres) down into the ice with a hot water drill and sent down several instruments to obtain readings from the glacier over a five-day period.
The devices included a torpedo-like robot named Icefin, which allowed them to investigate hitherto inaccessible places. The remotely operated vehicle captured photographs and data on water temperature and salinity, as well as ocean currents.
It could “swim up to these incredibly dynamic regions and capture data from the sea floor all the way to the ice,” according to Britney Schmidt, an associate professor at Cornell University and primary author on one of the publications.
The study’s findings reflect “a really nuanced and complex picture,” according to Peter Davis, an oceanographer at the British Antarctic Survey and a primary author on the second publication.
Even though the glacier is receding, the scientists discovered that the rate of melting beneath much of the flat area of the ice shelf was slower than expected. According to the study, the melt rate averaged 2 to 5.4 metres per year, which was lower than prior models predicted.
According to the study, melting is being slowed by a layer of colder, fresher water at the glacier’s base, between the ice shelf and the ocean.
“The glacier is still in peril,” Davis said in a statement, adding, “What we have discovered is that even little levels of melting, there is still rapid glacial retreat, indicating that it doesn’t take much to throw the glacier out of balance.”