Oceans' extreme depths measured in precise detail
Scientists say we now have the most precise information yet on the deepest points in each of Earth's five oceans.
The key locations where the seafloor bottoms out in the Pacific, Atlantic, Indian, Arctic and Southern oceans were mapped by the Five Deeps Expedition.
Some of these places, such as the 10,924m-deep (6.8 miles) Mariana Trench in the western Pacific, had already been surveyed a number of times.
But the Five Deeps project removed a number of remaining uncertainties.
For example, in the Indian Ocean, there were two competing claims for the deepest point - a section of the Java Trench just off the coast of Indonesia; and a fracture zone to the southwest of Australia.
The rigorous measurement techniques employed by the Five Deeps team confirmed Java to be the winner, but this lowest section in the trench - at a depth of 7,187m - is actually 387km from where previous data had suggested the deepest point might be.
Likewise, in the Southern Ocean, there is now a new place we must consider that region's deepest point. It's a depression called Factorian Deep at the far southern end of the South Sandwich Trench. It lies 7,432m down.
There is a location in the same trench, just to the north, that's deeper still (Meteor Deep at 8,265m) but it's technically in the Atlantic Ocean. The dividing line with the Southern Ocean starts at 60 degrees South latitude.