Scientists Discover Unprecedented Patterns Beneath Antarctica's Ice

In a groundbreaking expedition, scientists have uncovered never-before-seen patterns beneath the floating ice shelf of West Antarctica. These peculiar teardrop shapes were discovered under the Dotson Ice Shelf in 2022, during a mission aimed at creating the most detailed image of the glacier's underside.

Using a remotely operated vehicle (ROV), researchers ventured 10 miles (17 kilometers) beneath the glacier and traversed over 600 miles (1,000 kilometers) along the ice's underside. The findings from this extensive survey were published on July 31, 2024, in the journal Science Advances.

Anna Wahlin, a professor of oceanography at the University of Gothenburg and the study's lead author, explained the significance of these findings to Live Science: “To understand the ice cycle in Antarctica and how ice moves from the continent to the ocean, we need to comprehend how it melts from beneath. This process is as crucial as calving for transferring land ice to the ocean.”

The Dotson Ice Shelf, a 30-mile-wide (50 kilometers) expanse of floating ice, is located on the coast of Marie Byrd Land in West Antarctica. This shelf is part of the West Antarctic ice sheet, which contains rapidly calving glaciers that could potentially raise sea levels by approximately 11 feet (3.4 meters) if the entire sheet collapses.

The ice shelf is gradually being eroded by warm ocean water seeping underneath, detaching it from the land and making its eventual collapse a certainty, according to previous studies.

To investigate further, scientists deployed an ROV beneath the ice to sonar-scan the glacier's underside, producing the most comprehensive image to date. The survey confirmed that the glacier is melting fastest where underwater currents erode its base, with fractures facilitating the melt's rise to the surface.

Unexpectedly, the researchers also discovered that the glacier's base is dotted with teardrop-shaped formations protruding from peaks and valleys in the ice, some extending up to 1,300 feet (400 meters) long. Scientists believe these patterns result from uneven melting as water, influenced by Earth's rotation, moves across the glacier's underside.

“If you look closely, the shapes are not symmetrical; they are bent like blue mussels due to Earth's rotation,” Wahlin explained. “Water moving on Earth is subject to the Coriolis force, which acts to the left of the direction of motion in the Southern Hemisphere. If we are correct, there is a force balance in the layer closest to the ice where friction is balanced by the Coriolis force.”

This interaction results in a spiral flow pattern known as an Ekman spiral, typically seen when winds travel over surface water but also created by water moving over ice.