It's a truism among oceanographers that there is more accurate mapping of the surface of the moon and Mars than of the deep-ocean floor. That's especially true for the Bismarck Sea, a relatively deep body of water north of Papua New Guinea. It's an ocean basin with a geologically complex seafloor ri fe with faults, volcanic features, rifts, scarps, and active subduction and spreading zones at depths that make high-resolution sonar mapping challenging. ...read more read less