North Atlantic Secondary Subduction Zone
The North Atlantic Secondary Subduction Zone was an area in the Atlantic Ocean, where one tectonic plate moved sideways and down from the crust into the mantle under another plate. This zone, located west of the Mid-Atlantic Ridge, was selected as the site for the new subcontinent of New Atlantis. 
The location of this zone was labeled on a depiction of the Earth from Chapter 4, Page 31 of the New Atlantis Development Project Presentation Database. (, ''okudagram)

External link 
 
Earth geography