"Mapping Quest Edges Past 20% Of Global Ocean Floor"

"The quest to compile the definitive map of Earth's ocean floor has edged a little nearer to completion.

Modern measurements of the depth and shape of the seabed now encompass 20.6% of the total area under water.

It's only a small increase from last year (19%); but like everyone else, the Nippon Foundation-GEBCO Seabed 2030 Project has had cope with a pandemic.

The extra 1.6% is an expanse of ocean bottom that equated to about half the size of the United States."

Jonathan Amos reports for BBC News June 21, 2021.