Antarctica: Southern Ocean floor mapped in greatest ever detail

IBCSO/AWI/NIPPON FOUNDATION/SEABED2030

The most precise map of the mountains, canyons and plains that make up the floor of the Southern Ocean has been created by scientists.

The Factorian Deep is a depression lying 7,432m down on this chart for the first time.

Knowledge of the shape of the ocean's bottom is essential to safe navigation, marine conservativism, and understanding Earth's climate.

We still don't know a lot.

A lot of terrain has never been surveyed.

Five years have passed since the first attempt at a comprehensive map of the southern ocean was published.

We don't have a lot of knowledge of the bottom of the world's oceans.

Governments, corporations, and institutions are being urged not to hide away data and put as much as possible into the public domain. This is making money.

The southern ocean floor is covered by the new map. 23% of the cells have at least one modern depth measurement if you divide it into 500m grid squares.

Nine years ago, that was a big decline.

IBCSO/AWI/NIPPON FOUNDATION/SEABED2030

Less than a third of the grid boxes had a modern measurement back then.

The area of the chart has been doubled because of the change from 60 degrees to 50 degrees.

"We've increased the area coverage, but we've also increased the data density, because we've kept on acquiring new data and knocking on doors to free up existing data," he said.

The UK's former polar ship, the RRS James Clark Ross, is part of the information in the chart. The British contribution will come from the successor, the RRS Sir David Attenborough.

echo sounders make a habit of surveying the submerged terrain below as these vessels shuttle back and forth between the White Continent and other countries.

The activity is becoming more coordinated with research organizations from different nations working together to try to offset the routes taken by their icebreakers

The UK's new polar ship, the RRS Sir David Attenborough, has the ability to map millions of sq km of ocean bottom. There is a ship in the dry dock. There is a cover made of synthetic material over the 8m long array of transmitting transducers.

There are a lot of reasons for the need for better maps.

It is around the underwater mountains that marine wildlife tend to congregate that they are essential for safe navigation. The seamounts are a biodiversity hot spot.

The ocean currents and vertical mixing of water are influenced by the rugged seafloor. The oceans play a key role in moving heat around the planet and this information is needed to improve the models that forecast climate change.

"We can look at the ocean floor to see how the ice sheet has changed over thousands of years," said Dr Rob Larter.

There is a record of where the ice flowed and where it grounded. It is preserved in the shape of the ocean.

The funding for the new map came from Japan's Nippon Foundation and the SeaBed2030 effort to chart Earth's ocean floor by the end of the decade.

Our knowledge of four-fifths of the planet's underwater terrain comes from low-resolution satellite observations that show the presence of tall seamounts and deep valleys. There is a large submarine mountain with water on top of it.

The recognition of the Southern Ocean's deepest point is one of the key findings of the first and second versions. Factorian Deep is a depression at the south end of the South Sandwich Trench. There is 7,432m down. The Texan adventurer Victor Vescovo visited it in his submarine.

The remote and inhospitable nature of the Southern Ocean makes it difficult to map large swaths of it. There is high hope that an emerging class of robotic vessels will be able to do this task in the future.

Scientific Data publishes the International Bathymetric Chart of the Southern Ocean.