Southern Ocean pinnipeds provide bathymetric insights on the East Antarctic continental shelf

Depth data from over 500,000 tagged seal dives on the East Antarctic continental shelf improves the accuracy of seafloor bathymetry maps and reveals features not captured by ship-based mapping, including troughs off the Shackleton Ice Shelf and a deep canyon near the Vanderford Glacier. Poor coverage of the Antarctic continental shelf bathymetry impedes understanding the oceanographic processes affecting Antarctica's role in global climate. Continental shelf bathymetry influences warm modified Circumpolar Deep Water movement onto the shelf, making it an important factor promoting ice shelf melting and influencing the flow of ice shelves into the ocean. Building on previous work using seal dives to redefine bathymetry, our longitudinal study of ocean physics and animal behaviour provided new depth information from over 500,000 individual seal dives on the East Antarctic continental shelf. About 25% of these seal dives were 220 m (sometimes over 1000 m) deeper than the interpolated seafloor from IBCSO V2. Focusing on four well-sampled regions, we show that the bathymetry of 22% to 60% of the sampled area was improved by incorporating seal dive data. This revealed new bathymetric features, including troughs off the Shackleton Ice Shelf and Underwood Glacier and a deep canyon near the Vanderford Glacier. This deep canyon, the Mirounga-Nuyina Canyon, was confirmed by a recent multi-beam echo sounder survey. Further acquisitions of seal data will improve our understanding and modelling of Antarctic coastal ocean processes and ice-sheet dynamics.

Automated summary

Depth data from over 500,000 tagged seal dives on the East Antarctic continental shelf improves bathymetry maps and reveals new features. These data help understand the oceanographic processes affecting Antarctica's role in global climate. Incorporating seal dive data improves bathymetry of 22% to 60% of the sampled area, uncovering new features such as troughs and canyons.