What process causes subduction and seafloor spreading?
What process causes subduction and seafloor spreading?
Seafloor spreading and other tectonic activity processes are the result of mantle convection. Mantle convection is the slow, churning motion of Earth’s mantle. Convection currents carry heat from the lower mantle and core to the lithosphere.
Which process of conviction causes the spreading of the seafloor?
Seafloor spreading and other tectonic activity processes are the result of mantle convection. As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense.
What are the steps in the process of seafloor spreading?
Terms in this set (7)
- 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 are two pieces of evidence for 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 causes the seafloor to spread quizlet?
During sea-floor spreading, magma erupts along a mid-ocean ridge to form new oceanic lithosphere. The floor then moves away from the ridge, often toward a trench at the edge of the ocean basin. The pattern shows that ocean floor forms along mid-ocean ridges and then moves away from the ridge.
Where does subduction occur?
Pacific Ocean
Subduction zones occur all around the edge of the Pacific Ocean, offshore of Washington, Canada, Alaska, Russia, Japan and Indonesia. Called the “Ring of Fire,” these subduction zones are responsible for the world’s biggest earthquakes, the most terrible tsunamis and some of the worst volcanic eruptions.
What plate boundary causes subduction?
convergent plate boundaries
Subduction zones are where the cold oceanic lithosphere sinks back into the mantle and is recycled. They are found at convergent plate boundaries, where the oceanic lithosphere of one plate converges with the less dense lithosphere of another plate.
What causes plate 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. When an oceanic plate collides with a continental plate, the denser oceanic plate is bent downward and slides under the edge of the continent.
What process is involved when the oceanic crust plunges down into the mantle?
This process, called subduction, occurs at the oceanic trenches (figure 6). The entire region is known as a subduction zone. Subduction zones have a lot of intense earthquakes and volcanic eruptions. The subducting plate causes melting in the mantle.
What emerges from fissures causing sea floor spreading?
In the ocean, volcanoes erupt along cracks that are opened in the ocean floor by the spreading of two plates called a mid-ocean ridge . Magma from Earth’s upper mantle rises up to fill these cracks. As the lava cools, it forms new crust on the edges of the cracks.
What causes subduction?
What is the cause of seafloor spreading?
Like all geological processes which involves tectonic activity, seafloor spreading is caused by mantle convection. Mantle convection is the slow churning of the earth’s mantle which takes places beneath the earth’s surface. Convection currents transfer heat from the core and mantle of the earth up to the lithosphere,…
What is the difference between subduction and sea floor spreading?
Subduction occur when two plates converge towards each other and the denser plate being heavier slide below the lighter plate and Sea floor spreading occur at the Mid oceanic ridges where Diverging limbs of Convection cells tend to pull apart the plate and create a Rift Valley like the East African rift valley
What is the difference between sea floor spreading and mantle convection?
Seafloor spreading is a geologic process in which tectonic plates—large slabs of Earth’s lithosphere—split apart from each other. Seafloor spreading and other tectonic activity processes are the result of mantle convection. Mantle convection is the slow, churning motion of Earth’s mantle.
What is the difference between subduction and thermal convection?
This circulation appears to be thermal convection, with upwelling occurring beneath the seafloor spreading centers. The heat has two sources: 1) Leftover heat from the formation of the Earth 4.5 billion years ago, and 2) Decay of radioactive elements in the core and mantle. Subduction is the result of a room problem.
