Table of Contents
What is the process of seafloor spreading and subduction?
At subduction zones, the edge of the denser plate subducts, or slides, beneath the less-dense one. The denser lithospheric material then melts back into the Earth’s mantle. Seafloor spreading creates new crust. Subduction destroys old crust.
Which parts of sea floor spreading and subduction were not shown in your model?
Ocean-floor spreading is a process in which plates cause the sea floor to spread or move apart and new oceanic crust is continually formed in the process. The part of the process that is not shown is the molten material seeping into the Mid-Ocean Ridge, and process of subduction is not shown as well.
What causes sea floor spreading?
Sea-floor spreading is what happens at the mid-oceanic ridge where a divergent boundary is causing two plates to move away from one another resulting in spreading of the sea floor. As the plates move apart, new material wells up and cools onto the edge of the plates.
Who developed the idea of seafloor spreading model?
The seafloor spreading hypothesis was proposed by the American geophysicist Harry H. Hess in 1960.
What causes subduction?
These plates collide, slide past, and move apart from each other. Where they collide and one plate is thrust beneath another (a subduction zone), the most powerful earthquakes, tsunamis, volcanic eruptions, and landslides occur.
What occurs during subduction?
Subduction occurs when two plates collide at a convergent boundary, and one plate is driven beneath the other, back into the Earth’s interior. Not all convergence leads to subduction. Continental rocks are too buoyant to be forced downward, so when continents collide, they crumple but stay at the surface.
Who proposed the seafloor spreading theory?
Harry Hess
Harry Hess: One of the Discoverers of Seafloor Spreading.
What is the importance of seafloor spreading theory?
Significance. Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere.
What is the history of the theory of sea floor spreading?
Seafloor spreading was proposed by an American geophysicist, Harry H. Hess in 1960. By the use of the sonar, Hess was able to map the ocean floor and discovered the mid-Atlantic ridge (mid-ocean ridge). He also found out that the temperature near to the mid-Atlantic ridge was warmer than the surface away from it.
What is process of subduction?
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth’s mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle.
Where does subduction occur in the ocean?
The subduction zone, accordingly, is the antithesis of the mid-oceanic ridge. New seafloor is generated from the upper mantle at the mid-oceanic ridges, spreads laterally outward, and is eventually subducted, or consumed, at the margins of ocean basins.
How subduction cause the formation?
Due to the heat caused by it rubbing against the other plate as well as the natural heat of the mantle, the plate melts and turns into magma. The area where subduction occurs is known as the subduction zone. When one plate begins to slip underneath another one a trench is formed.
What evidence supports the theory of seafloor spreading?
Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material, magnetic stripes, and drilling samples. This evidence also led sci- entists to look again at Wegener’s theory of continental drift.
What are the steps in the process of sea floor spreading?
What are the steps in the process of sea floor spreading? Magma comes out of the rift valley. Magma cools to rock and hardens. Rock is pushed away as new rock is formed at MOR. Oceanic crust and continental crust meet at the trench. Oceanic crust bends down under the continental crust. Gravity pulls rock towards mantle. Rock melts to mantle.
What is the process of sea floor spreading?
Magma comes out of the rift valley.
What are facts about seafloor spreading?
• Seafloor spreading is the movement of two oceanic plates away from each other (at a divergent plate boundary), which results in the formation of new oceanic crust (from magma that comes from within the Earth’s mantle) along a mid- ocean ridge. Where the oceanic plates are moving away from each other is called a zone of divergence.
What evidence exists for sea floor spreading?
Sea floor continues to spread apart as new crust is added. Processes repeats like a conveyor belt, carrying continents along with them. Evidence supported Hess’s theory of sea-floor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves.