Seventy-one percent of the planet is covered by ocean. If we were to make an elevation average of the Earth’s surface, we’d be 3,000 meters (almost 10,000 feet) below the sea. This vast expanse is poorly known and understood, but the global initiative Seabed 2030, from the Nippon Foundation-GEBCO, has set out to remedy this. Its goal? To map the whole ocean floor by the end of this decade.
This goal is extremely ambitious. There are technical challenges, financial challenges, and political challenges. Five years to get most of the ocean mapped might be a tall order, but there are developments in the works that might make the goal both affordable and achievable in the shorter term.
One such approach delivered new coastal mapping data across 14 different countries. Totaling 217,560 square kilometers (84,000 square miles) with an average resolution of 100 meters (328 feet), the mapping covers many regions that had not been charted before, from the Solomon Islands to Baja California.
The work was conducted by the Greenwater Foundation with the support and guidance of Victor Vescovo’s Caladan Oceanic.
In areas where the sea is clear, mapping is done using light instead of sonar up to a depth of 30 meters (about 100 feet). Usually, it is done with boats or airplanes, which is often time and fuel-consuming. The groups involved instead used a method called satellite-derived bathymetry (SDB), using satellite data to craft these detailed maps.
“We were able just last year to map a quarter of a million square kilometers for approximately $2 per square kilometer, which is in order of magnitude cheaper than you could ever have done it,” Victor Vescovo told IFLScience. “In shallow water, sonar beams can’t travel very far. So the amount of area you can map using sonar with a ship is very small, which makes it very cost-ineffective. But a satellite can view vast areas all at once.”
The data was shared with the respective countries and the Seabed 2030 groups. The team is investigating how to train a machine learning tool to assist operators in creating even more maps of coastal areas, with even more efficiency, and accuracy. It might be possible to reach a precision of less than 1 meter (3 feet).
Vescovo has been thinking about mapping the seafloor for a long time. He’s mostly known for an incredibly long list of exploration records, including being the first person to dive to the deepest location of all five of the world’s oceans. He told us that one of the shocking findings in the preparation of the Five Deeps expedition was the fact that we didn’t know the deepest point for four of those five oceans. The uncertainty in the actual location was in the order of hundreds of kilometers.
The mission was successful, but it required Vescovo and his team to map swathes of the oceans, and it became clear that a major challenge in actually mapping the ocean was the cost. His work since then has been focused on reducing the cost of mapping the remaining 74 percent of unknown seabed.
Coastal areas can be mapped with satellites, as has been demonstrated. For the deeper seas and ocean, Vescovo has a bold new proposal. Where the water is too deep for light to penetrate, but it is still in an area near enough to the coast, with a depth between 30 and 500 meters (98 and 1,640 feet), automated vehicles can sail up and down an area, mapping as they go along.
There is a good reason why we haven’t mapped the seafloor: it’s not worth that much directly, but I think in terms of a common good, it is.
Victor Vescovo
“That’s where the ship that I’m designing and hopefully will build in the next two years will come to the fore. With a crew of just one person, maybe two, it will effectively be a semi-autonomous ship that will go out for two to three weeks at a time and run large tracks with the most powerful mapping sonar you can put on a civilian vessel, the Kongsurury EM124. That is a sonar that can map thousands of square kilometers per day because that’s what it’s designed to do. And you have the depth to get a large swath of area,” Vescovo explained to IFLScience.
There are currently around 300 million square kilometers (116 million square miles) of unmapped seafloor. Bringing the cost per square kilometer down to a handful of dollars makes this costly task suddenly far more affordable.
“There is a good reason why we haven’t mapped the seafloor: it’s not worth that much directly, but I think in terms of a common good, it is. From helping with navigation for ships so they don’t run into sea mounts or shoals that they don’t know about, to mapping the tidal areas and the ocean current areas to help with climate modeling, all of those are common goods that are hard to get funded, but if we make it cheap enough, maybe we are able to make it approachable,” Vescovo told IFLScience.
Vescovo is fond of stressing the economic argument. Our chat took place as he was on his way to Brussels to discuss deep-sea mining with European politicians. Even there, he was not going to argue about the serious environmental impact or technological challenges; his arguments boil down to that it doesn’t make economic sense and it won’t work.
The surface of Mars and the Moon is better mapped than the seafloor, but thanks to the confluence of technology from automation, machine learning, satellite communications, and more, we might be getting closer to closing the gap. Five years might still be too short of a time to completely map the ocean floor, but the first global map might no longer be decades away.
