Beneath Antarctica’s Dotson Ice Shelf lies a world previously unknown to scientists—a landscape of peaks, valleys, and teardrop-shaped formations etched by melting ice and ocean currents. This groundbreaking discovery is offering valuable insights into the processes driving ice melt and their global implications.
Antarctica’s Upside-Down Terrain Stripped Open
In 2022, an international research team led by Professor Anna Wåhlin from the University of Gothenburg used the unmanned submersible Ran to explore the underside of the Dotson Ice Shelf in West Antarctica. For 27 days, the submersible navigated 1,000 kilometers under 350 meters of ice, creating the first-ever map of an ice shelf’s basal topography.
What the team found was startling: the ice shelf’s underside resembled a vast, otherworldly landscape with features like plateaus, swirly erosion patterns, and massive scooped-out formations. These discoveries offered an unprecedented glimpse into the interactions between warm ocean currents and ice, shedding light on how Antarctic ice is melting.
“It looked like the Grand Canyon. There were plateaus and swirly patterns melted into the ice” – Anna Wåhlin
The Role of Ice Shelves in Sea Level Rise
Ice shelves like Dotson float on the ocean, and their melting does not directly raise sea levels. However, they play a crucial role in buttressing land-based glaciers, preventing their flow into the sea. As these shelves thin or collapse, glaciers behind them accelerate toward the ocean, contributing to global sea level rise.
The Dotson Ice Shelf is thinning faster than other ice shelves in the Amundsen Sea region, driven by warm ocean currents spreading southward. The nearby Thwaites Glacier, often called the “Doomsday Glacier,” is particularly concerning. If it fully melts, it could raise global sea levels by up to 65 centimeters.
Ecological Shifts in the Amundsen Sea
The melting ice is not only a threat to sea levels but also to the unique ecosystems of the Amundsen Sea. Meltwater from the Dotson Ice Shelf carries iron, fueling phytoplankton blooms that form the base of the Antarctic food web. These microscopic organisms absorb significant amounts of carbon dioxide, playing a critical role in climate regulation.
Oceanographer Patricia Yager likened the under-ice environment to a vibrant coral reef. However, rapid ice melting is altering the salinity and stability of the ocean, potentially disrupting these delicate ecosystems and the carbon cycles they support.
Challenges in Antarctic Research
In 2024, Wåhlin’s team returned to continue mapping the underside of the Dotson Ice Shelf, but the mission ended abruptly when Ran disappeared under the ice. Despite the setback, the research highlighted the complexities of exploring such extreme and remote environments. The team suspects marine mammals, like Weddell seals, may have interfered with the submersible, causing it to fail.
Still, the mission revealed patterns and structures beneath the ice that defy current scientific models, indicating much remains to be learned about the processes shaping Antarctica’s ice.
