The surface of Mars has been mapped more thoroughly than the floor of Earth's oceans. That fact, startling as it is, reflects nothing more than the relative difficulty of the two tasks: radar works in a vacuum; it does not work through kilometres of seawater.
The Seabed 2030 initiative aims to change that by the end of the decade, using a global network of research vessels equipped with multibeam sonar. As of this year, coverage has reached approximately 24 percent.
The urgency has increased as researchers document the pace of change in deep-water ecosystems. Thermal stratification driven by surface warming is altering circulation patterns that have been stable for millennia.
