As much as we struggle to understand the depths of outer space, we are also still struggling to map our own planet. Getting to the seafloor requires us to build vessels capable of surviving extreme pressure, coldness, and making measurements in utter darkness. In some ways, designing for the vacuum of space is far easier, actually, and if a spacecraft springs a leak, it can probably be repaired with a space version of duct tape. That doesn’t work with high-pressure water.

This is where we find, working parallel to space explorers, a company of aquanauts who are trying to define what lies beneath the seas. In a new study, answering one simple question – where are the deepest points in each ocean? – proved far more difficult than thought. The Five Deeps Expedition has published new depth data in the Geoscience Data Journal and documented that while the 10,924-meter deep Mariana Trench remains the deepest point in all the oceans, other deep spots aren’t quite where we expected. 

For instance, we’d thought there was a particularly deep trench off the coast of Java, and there is; it just happens that the lowest section of the trench is nearly 400 kilometers away from where we’d thought. Ingloriously named Unnamed Deep, this trench descends to 7,187 meters. In the Southern Ocean, along the trench spanning from South America toward Antarctica, there is also a newly discovered spot, named Factorian Deep, that lies at 7,432 meters down.

This is a reminder that the oceans are more vast than the land. Mount Everest reaches up to only 8,849 meters, and the deepest parts of the ocean are more than 10,000 meters down. Now, instead of asking “Why do we climb?”, we need to start asking “Why do we descend?”

More Information

Oceans’ extreme depths measured in precise detail (BBC)

“High-resolution multibeam sonar bathymetry of the deepest place in each ocean,” Cassandra Bongiovanni, Heather A. Stewart, and Alan J. Jamieson, 2021 May 5, Geoscience Data Journal