Submarine canyons are vast, deep formations located on the majority of the world’s continental margins. Antarctica plays a pivotal role in marine processes that significantly influence global climate and ocean circulation. The understanding of oceanographic, climatic, geological, and ecological importance is often hindered by the limitations in Canyon data. In a recent study, researchers from University College Cork and the University of Barcelona aimed to develop the most comprehensive catalogue of Antarctic submarine canyons and gullies. They discovered 332 drainage networks consisting of 3,291 river segments, which is nearly five times the number of canyons recorded in earlier research.
This map shows a network of 332 submarine canyons on the seabed of Antarctica. Image credits: Riccardo Arosio & David Amblas, doi: 10.1016/j.margeo.2025.107608.
Submarine canyons are prevalent features found along all continental margins.
These canyons are typically V-shaped valleys with narrow, flexible morphology, beginning at the edge of the continental shelf or continental slope and extending into either the continental rise or abyssal plains.
Short channels less than 10 km in length are referred to as submarine gullies, and they are commonly found within canyon systems on continental slopes.
Submarine canyons are crucial for transporting sediments and nutrients from coastal areas to deeper waters, establishing biodiverse habitats by linking shallow and deep marine environments.
While approximately 10,000 submarine canyons exist globally, only 27% of the ocean floor is mapped at high resolution, indicating a likely higher total number of canyons.
Despite their ecological, oceanographic, and geological significance, submarine canyons are often underrepresented, especially in polar regions.
“Similar to the submarine canyons in the Arctic, those in Antarctica mirror canyons found elsewhere in the world,” stated Dr. David Amblàs, a researcher at the University of Barcelona.
“Yet, they tend to be larger and deeper due to the prolonged effects of polar ice and the considerable volume of sediment that glaciers deposit onto the continental shelf.”
For their research, the authors utilized version 2 of the International Bathymetric Chart of the Southern Ocean (IBCSO V2), the most comprehensive and detailed seabed map for the region.
They employed new high-resolution seabed data alongside semi-automated methods to identify and analyze these canyons.
Overall, they described 15 morphometric parameters that displayed notable differences between the southeastern and western canyons.
“Some of the submarine canyons we examined exceed depths of 4,000 meters,” remarked Dr. Amblàs.
“The most impressive among them is located in East Antarctica and consists of a complex, divergent canyon system.”
“It originates from multiple canyons near the edge of the continental shelf and converges into a single main channel that descends steeply into deep water.”
Dr. Ricardo Arosio from Cork University commented:
“The canyons in East Antarctica exhibit more complexity and branching patterns, forming varied canyon channel systems characterized by the often typical U-shaped cross sections.”
“This indicates a significant influence of long-term development under persistent glacial activity alongside erosion and sediment deposition processes.”
“On the contrary, West Antarctic canyons are short and steep, featuring a V-shaped cross section.”
“This morphological distinction supports the hypothesis that the East Antarctic ice sheet developed earlier and underwent a longer maturation process,” explained Dr. Amblàs.
“This was previously suggested by studies of sedimentary records but lacked explanation through large-scale seabed geomorphology.”
“Thanks to the high resolution of the new seabed measurement database—500 m per pixel, compared to 1-2 km per pixel in earlier maps—we can effectively apply semi-automated technology for canyon identification, profiling, and analysis,” Dr. Arosio stated.
“The strength of our research lies in the integration of various methods previously used but now brought together into robust and systematic protocols.”
“We’ve also developed a GIS software script that enables the calculation of numerous canyon-specific morphometric parameters with just a few clicks.”
The team’s research will be featured in the journal Marine Geology.
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Riccardo Arosio & David Amblas. 2025. Topographic measurements of the Antarctic Submarine Canyon. Marine Geology 488:107608; doi:10.1016/j.margeo.2025.107608
Source: www.sci.news
