Sea Floor Spreading Deep Ocean Trenches

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 deep ocean trenches.

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. Deep ocean trenches are surficial evidence for. Seafloor spreading occurs along mid ocean ridge s large mountain range s rising from the ocean floor. Depth below seafloor is a vertical coordinate used in geology paleontology oceanography and petrology see ocean drilling.

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 ocean floor generally does not just keep spreading. First related the symmetrical magnetic patterns in seafloor basalts to sea floor spreading at a mid ocean ridge.

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

What happens to old oceanic crust as new molten material rises from the mantle. See also continental drift a veritable legion of evidence supports the seafloor spreading hypothesis. New oceanic crust is hot. The new material splits apart the old material and pushes it outward from the ridge.

Oceanic trenches are topographic depressions of the sea floor relatively narrow in width but very long. 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. Sea floor spreading and subduction work together. They move the ocean floor as if it were on a giant conveyor belt.

As subduction occurs crust closer to a mid ocean ridge moves away from the ridge and toward a deep ocean trench. At a deep ocean trench the oceanic crust bends downward. Instead the ocean floor plunges into deep underwater canyons called deep ocean trenches. A trench marks the position at which the flexed subducting slab begins to descend beneath another lit.

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.