What is the process by which the ocean floor sinks beneath a deep ocean trench and back into the mantle?
Subduction is the process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle.
What happens to old oceanic crust?
What happens to old oceanic crust as new molten material rises from the mantle? It is recycled back into the mantle through the process of subduction. The process of subduction also plays a role in the new molten material rising from the mantle (see page 132).
What happens to the old seafloor as it is pushed into the mantle?
When the seafloor subducts it does disappear from the surface. It moves deeper into the Earth, into the mantle. But in the Pacific ocean there are also ridges, called spreading centers, where new seafloor is created.
What will happen to the oceanic crust that is pushed down at the trench?
As it moves down into the subduction zone, our crust is pushed down under another plate. It bends down and starts to sink into the mantle – the older the crust, the steeper the angle. Subduction zones and mid-ocean ridges are linked. In them, creation and destruction is broadly balanced.
What happens when two plates carrying oceanic crust collide?
When two plates collide, the density of the plates determines which one comes out on top. Oceanic crust is more dense than continental crust. When two plates carrying oceanic crust meet at a trench, the plate that is less dense dives under the other plate and returns to the mantle. This is the process of subduction.
What happens when two oceanic crust collides with each other?
A subduction zone is also generated when two oceanic plates collide — the older plate is forced under the younger one — and it leads to the formation of chains of volcanic islands known as island arcs.
What do you think will happen when two oceanic plates move towards each other?
When oceanic or continental plates slide past each other in opposite directions, or move in the same direction but at different speeds, a transform fault boundary is formed. No new crust is created or subducted, and no volcanoes form, but earthquakes occur along the fault.
When two oceanic plates collide which one loses and Subducts underneath the other one?
Convergent Plate Boundaries When a plate of dense oceanic lithosphere moving in one direction collides with a plate moving in the opposite direction, one of the plates subducts beneath the other. Where this occurs an oceanic trench forms on the sea floor and the sinking plate becomes a subduction zone.
What cause the plates to move?
The heat from radioactive processes within the planet’s interior causes the plates to move, sometimes toward and sometimes away from each other. This movement is called plate motion, or tectonic shift.
What is it called when one plate moves under another?
Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced to sink due to high gravitational potential energy into the mantle. Regions where this process occurs are known as subduction zones.
What zone is created when two plates move apart?
Divergent boundaries
What plate boundary happens when two plates slowly crash into each other?
When plates crash or crunch together are called “Convergent Boundaries”. the Plates only move a few centimeters every year, so collisions are very slow and last millions of years.
What happens if two plates rub against each other?
As the plates rub against each other, huge stresses can cause portions of the rock to break, resulting in earthquakes. Places where these breaks occur are called faults. A well-known example of a transform plate boundary is the San Andreas Fault in California.
What happens when 2 tectonic plates separate?
The plates diverge and this causes the construction of new rock. It happens when two tectonic plates pull apart and rock from the mantle rises up through the opening to form new surface rock when it cools. See volcanoes for more on the effects of divergent plate boundaries (redirect to Topics section).
When two tectonic plates pull apart a is formed on the ocean floor?
As plates made of oceanic crust pull apart, a crack in the ocean floor appears. Magma then oozes up from the mantle to fill in the space between the plates, forming a raised ridge called a mid-ocean ridge. The magma also spreads outward, forming new ocean floor and new oceanic crust.
What causes the tectonic plates to break apart?
Earthquakes occur along fault lines, cracks in Earth’s crust where tectonic plates meet. They occur where plates are subducting, spreading, slipping, or colliding. As the plates grind together, they get stuck and pressure builds up. Finally, the pressure between the plates is so great that they break loose.
What are the major causes and effects of tectonic plate movements?
They have also caused faults, cracks in the earth’s crust. Shifts along a fault can also cause earthquakes or violent jolts in the area around it. In coastal areas undersea earthquakes can cause huge waves known as Tsunamis to erupt. Plate tectonics cause folding of rock layers into mountains.
What will happen if tectonic plates continue to move?
Plate tectonics moves the continents around on a scale of 100s of millions of year. Plate tectonics also has an impact on longer-term climate patterns and these will change over time. It also changes ocean current patterns, heat distribution over the planet, and the evolution and speciation of animals.
What happens during ridge push?
“ridge push” The lithosphere thickens with distance (and time) away from the midocean ridge. The result of this thickenning with distance from the ridge is that the lithosphere/asthenosphere boundary slopes away from the ridge. The weight of the lithosphere on this sloping surface produces a downslope force.
What are the effects of ridge push?
Ridge push is the result of gravitational forces acting on the young, raised oceanic lithosphere around mid-ocean ridges, causing it to slide down the similarly raised but weaker asthenosphere and push on lithospheric material farther from the ridges.
What is the process of slab pull?
Slab pull is the pulling force exerted by a cold, dense oceanic plate plunging into the mantle due to its own weight. The process of a tectonic plate descending into the mantle is termed subduction. Slab pull occurs when an oceanic plate subducts into the underlying mantle.
In what way the ridge push and slab pull causes plate to move?
What would cause that? Current dynamic models have plates moving as part of a gravity-driven convection system that pushes young hot plates away from spreading ridges and pulls old cold plates down into subduction zones.
Why slab pull is important?
Stresses are transmitted more efficiently within stronger slabs and, hence, slab rheology exerts an important influence on the slab pull force. [4] Despite the potential importance of both slab pull and continental roots, their relative influence on global patterns of plate motions has not yet been determined.