The deepest point of the Southern Ocean surrounding Antarctica – a 7,432-meter (24,383-foot) deep trench called the Factorian Deep – has been closely detailed in a new project to map this vast sea floor. An international team of scientists revealed their efforts to map the icy depths of the Southern Ocean floor in a study published earlier this month, reported in the journal Scientific Data.

The results are the most extensive map yet of this corner of the world yet, covering a total area of 48 million kilometers squared (18.5 million miles squared), an area roughly five times the size of Canada. A high-resolution map of the Southern Ocean can be downloaded free from the project's website: www.ibcso.org. 

Along with displaying the ocean’s many mountains, mounds, and troughs in never-before-seen detail, it also shows the new deepest point of the Southern Ocean found in South Sandwich Trench: the Factorian Deep.

Remarkably, the Factorian Deep was visited by explorer Victor Vescovo in 2019 as part of his Five Deeps Expedition, in which he became the first person to reach the bottom of the Southern Ocean.

Satellite data of the Southern Ocean has been around for a while, but this imagery lacks some of the finer details picked up by ship-based methods of mapping the seafloor. 

For this latest project, the team gathered data from multibeam echosounder readings taken in the Southern Ocean by an array of research vessels such as the icebreaker Polarstern and the British Antarctic Survey’s former ship RRS James Clark Ross. In the future, data will also be gathered by RRS Sir David Attenborough, the research vessel launched in 2018 that famously accompanies the Boaty McBoatface submarine.

Better maps of the Southern Ocean have the very real potential to boost our understanding of this vital region of Earth. The waters around Antarctica host an abundance of unique biodiversity and can provide invaluable insights into our planet’s geological history and its climate. The better researchers can navigate this mysterious environment, the more we can learn. 

“No matter where you travel or work, you need a map for orientation. That’s why virtually all oceanographic disciplines rely on detailed maps of the ocean floor,” Dr Boris Dorschel-Herr, lead study author and Head of Bathymetry at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, said in a statement. 

“For example, the seafloor topography of the Southern Ocean is essential to understanding a range of climate-relevant processes. Warm water masses flow into deep troughs in the continental shelf towards the ice shelves and glaciers of the Antarctic, affecting how they melt. Conversely, the stability and calving behaviour of glaciers and ice sheets greatly depend on the features of the ground beneath them. With the IBCSO v2, we have delivered the best and most detailed representation of the Southern Ocean to date,” added Dorschel-Herr.