Sea Floor Spreading Deep Ocean Trenches

The process by which ocean floor sinks beneath a deep ocean trench and back into the mantle is called subduction sub duk shun.

Sea floor spreading deep ocean trenches. As subduction occurs crust closer to a mid ocean ridge moves away from the ridge and toward a deep ocean trench. First related the symmetrical magnetic patterns in seafloor basalts to sea floor spreading at a mid ocean ridge. See also continental drift a veritable legion of evidence supports the seafloor spreading hypothesis. The new material splits apart the old material and pushes it outward from the ridge.

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. Depth below seafloor. 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. The mid atlantic ridge for instance separates the north american plate from the eurasian plate and the south american plate from the african plate.

Sea floor spreading and subduction work together. Seafloor spreading occurs along mid ocean ridge s large mountain range s rising from the ocean floor. At a deep ocean trench the oceanic crust bends downward. Instead the ocean floor plunges into deep underwater canyons called deep ocean trenches.

These oceanographic features are the deepest parts of the ocean floor. What happens to old oceanic crust as new molten material rises from the mantle. Depth below seafloor is a vertical coordinate used in geology paleontology oceanography and petrology see ocean drilling. The ocean floor generally does not just keep spreading.

Maps and other data gathered during the war allowed scientists to develop the seafloor spreading hypothesis. 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. Subduction takes place at. 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.

This hypothesis traces oceanic crust from its origin at a mid ocean ridge to its destruction at a deep sea trench and is the mechanism for continental drift during world war ii battleships and submarines carried echo sounders to locate enemy submarines. Oceanic trenches are topographic depressions of the sea floor relatively narrow in width but very long. Deep ocean trenches are surficial evidence for. Sinking of oceanic lithosphere into the mantle at a subduction zone.

New oceanic crust is hot.