Remote vehicle reveals hidden shapes under Antarctic glacier

"In order to understand the ice cycle in Antarctica and how ice gets from the continent into the ocean, we need to understand how it melts from beneath," say scientists. Therefore, they decided to explore the bottom of the glacier using a remotely controlled vehicle. They discovered something there that had never been seen before. The sight of several hundred-foot-long shapes must have sent chills down their spines.

The strange and unknown shapes at the bottom of the Dotson Glacier in the western part of Antarctica were discovered by scientists back in 2022. However, detailed studies about this discovery were only recently published in the journal "Science Advances." The researchers decided to lower a remotely controlled vehicle to a depth of 10 miles under the glacier, which travelled 620 miles along the ice.

The expedition to the bottom of the drifting ice sheet provided the most accurate images of the glacier bed to date and helped identify shapes several hundred feet long that may help better understand the process of glacier melting.

"In order to understand the ice cycle in Antarctica and how ice gets from the continent into the ocean we need to understand how it melts from beneath, a process that is equally important as calving for moving land ice to the ocean," explains Anna Wåhlin, the study's lead author and an oceanography professor at the University of Gothenburg (Sweden), in an interview with Live Science.

The Dotson Glacier, studied by scientists, is a 30-mile-wide piece of ice located on the coast of Marie Byrd Land (West Antarctica). It is considered an area that could cause a rise in sea levels by about 11 feet due to the collapse of the ice sheet. Previous studies have shown that warm ocean water is gradually eroding the ice shelf's underside, making its collapse inevitable.

Thus, scientists studied how the process of melting glaciers from underneath looks. According to Live Science, using the aforementioned remotely controlled vehicle equipped with sonar, they obtained the most accurate image of the lower part of the glacier ever created. The sonar study determined that the glacier melts fastest in areas where underwater currents erode its base. Cracks running through the glacier facilitate the movement of melting ice toward the surface.

The Antarctica research team was surprised to find that the glacier's base is not smooth, as expected, but instead covered with numerous tear-shaped forms in peaks and valleys in the ice. Some of these formations are up to 1,310 feet long and, according to scientists, are created by uneven melting as water moves along with the Earth's rotation under the glacier.

"If you look closely at the shapes they are not symmetrical, they are bent a bit like blue mussels, and the reason for that asymmetry is Earth's rotation," explains Wåhlin. The study's lead author clarifies that this phenomenon is related to the presence of the Coriolis force. "Water moving on Earth is subject to something called the Coriolis force, which is acting to the left of the direction of motion in the Southern Hemisphere," she adds. This force results in a specific spiral pattern known as the Ekman spiral, which is primarily visible on the water's surface but can also form as water moves under the ice.

Scientists decided to continue their research in January 2024, but they lost the remotely controlled vehicle during the expedition. It got lost under the ice shelf, so the next goal for the team was to arrive under the glacier with another vehicle and continue their studies.