🏔️ A vast network of giant canyons discovered beneath Antarctica

High-resolution mapping of the Antarctic seafloor has revealed the existence of 332 submarine canyons, a number far greater than previous estimates. These major geological structures, some of which descend to depths of more than 4000 meters (about 2.5 miles), play a fundamental role in global ocean circulation and the stability of ice shelves.

A contrasting submarine geography

The eastern coast of the continent hosts complex, branched systems. These canyons exhibit wide U-shaped profiles, indicating a long evolution under the persistent action of glaciers. Their multiple heads often converge toward a single main channel.

The western coast presents a radically different underwater landscape. The canyons there are generally shorter and steeper. Their walls form narrow V-shaped gorges, characteristic of more recent and intense erosion processes.

This morphological divergence supports a major geological hypothesis. The East Antarctic ice sheet is believed to have a much older origin than its western counterpart. Previous sediment studies corroborate this interpretation.

Key players in the climate system

These submarine valleys function as highways for water masses. They facilitate exchanges between deep waters and the continental shelf. This mechanism is vital for the formation of cold, dense waters.

The canyons also channel warmer waters toward the coasts. This process accelerates the basal melting of floating ice shelves. The stability of continental glaciers depends directly on this.

The absence of these structures in climate models limits their accuracy. Projections of sea level rise could thus gain in reliability. Better integration of these landforms is therefore essential.