Sea Floor Spreading Deep Ocean Trenches

Deep valley or underwater canyon where the oceanic crust sinks back toward the mantle subduction the process by which the ocean floor sinks beneath a deep ocean trench and back into the mantle.

Sea floor spreading deep ocean trenches.

They move the ocean floor as if it were on a giant conveyor belt. In sea floor spreading new crust is added at a. These oceanographic features are the deepest parts of the ocean floor. Maps and other data gathered during the war allowed scientists to develop the seafloor spreading hypothesis.

Deep ocean trenches are surficial evidence for. The process by which ocean floor sinks beneath a deep ocean trench and back into the mantle is called subduction sub duk shun. Seafloor spreading occurs along mid ocean ridge s large mountain range s rising from the ocean floor. What happens to old oceanic crust as new molten material rises from the mantle.

Oceanic trenches are a distinctive morphological feature of convergent plate boundaries along which lithospheric plates move towards each other at rates that vary from a few millimeters to over ten centimeters per year. Subduction takes place at. First related the symmetrical magnetic patterns in seafloor basalts to sea floor spreading at a mid ocean ridge. The new material splits apart the old material and pushes it outward from the ridge.

Sinking of oceanic lithosphere into the mantle at a subduction zone. Wherever continents are bordered by deep sea trench systems as in the pacific ocean the ocean floor is plunged downward underthrusting the continents and ultimately reentering and dissolving in earth s mantle from which it had originated. A trench marks the position at which the flexed subducting slab begins to descend beneath another lit. The hadal zone which includes the oceanic trenches lies between 6 000 11 000 metres 20 000 36 000 ft and is the deepest oceanic zone.

See also continental drift a veritable legion of evidence supports the seafloor spreading hypothesis. The mid atlantic ridge for instance separates the north american plate from the eurasian plate and the south american plate from the african plate. Depth below seafloor. Depth below seafloor is a vertical coordinate used in geology paleontology oceanography and petrology see ocean drilling.

New oceanic crust is hot. Oceanic trenches are topographic depressions of the sea floor relatively narrow in width but very long. Sea floor spreading and subduction work together. At a deep ocean trench the oceanic crust bends downward.

The ocean floor generally does not just keep spreading.