New Discovery: 332 Submarine Canyons Found Beneath Antarctica

In August 2025, researchers from the University of Barcelona and University College Cork unveiled a comprehensive map detailing 332 submarine canyons beneath Antarctica's ice shelves, some plunging over 4,000 meters deep. This discovery, published in Marine Geology, significantly enhances our understanding of the Antarctic seafloor and its influence on global ocean circulation and climate dynamics.

The study utilized high-resolution bathymetric data from more than 40 international research expeditions, revealing a fivefold increase in the number of known Antarctic submarine canyons. These canyons serve as critical conduits for water, sediments, and nutrients between the continental shelf and the deep ocean, playing a pivotal role in oceanographic processes.

Submarine canyons are steep-sided valleys that cut into continental margins worldwide. In Antarctica, these formations are generally larger and deeper due to prolonged glacial activity and the immense volumes of sediment transported by glaciers to the continental shelf. The newly identified canyons exhibit distinct regional characteristics:

• East Antarctic Canyons: These are complex, branching systems with U-shaped profiles, indicating prolonged development under sustained glacial activity.

• West Antarctic Canyons: Characterized by shorter, steeper, V-shaped profiles, suggesting more recent glacial processes.

These morphological differences support the hypothesis that the East Antarctic Ice Sheet originated earlier and has experienced more prolonged development compared to its western counterpart.

The canyons significantly influence ocean circulation by facilitating the exchange between cold, dense water near ice shelves and deep ocean layers, contributing to the formation of Antarctic Bottom Water—a key component of global ocean circulation. Additionally, they channel warmer ocean waters from the open sea toward the coastline, a process that drives the basal melting and thinning of floating ice shelves. This melting is critical for maintaining the stability of Antarctica's interior glaciers.

Despite their importance, the impact of these canyons is not fully incorporated into current climate models. With only about one-third of the seafloor accurately charted, there is a lack of detailed knowledge about these features. Current ocean circulation models do not accurately reproduce the physical processes that occur at local scales between water masses and complex topographies like canyons. This omission may hinder accurate predictions about ocean behavior and global climate changes.

Understanding these submarine canyons is crucial for developing effective climate change mitigation and adaptation strategies. Their role in transporting warmer waters to ice shelves contributes to ice shelf thinning and potential collapse, leading to accelerated glacial flow and increased sea-level rise.

The discovery of these submarine canyons beneath Antarctica's ice shelves underscores the intricate connections between geological formations and global climate systems. Incorporating this knowledge into climate models is essential for accurate predictions and effective responses to climate change.