The Manus Plate is forming in an active back-arc basin north of Papua New Guinea, where extension behind a subduction zone is creating new oceanic crust. The Manus Basin hosts black smoker hydrothermal vents with some of the hottest vent fluids ever recorded, exceeding 400°C. These vents support unique extremophile organisms and have attracted significant scientific interest for astrobiology research.

This plate is entirely oceanic with no land masses.