What does the tectonic plates do?
The theory of plate tectonics states that the Earth’s solid outer crust, the lithosphere, is separated into plates that move over the asthenosphere, the molten upper portion of the mantle. Oceanic and continental plates come together, spread apart, and interact at boundaries all over the planet.
Where does New lithosphere form quizlet?
New lithosphere forms in divergent plate boundaries and is consumed at subduction zones – largely about the rim of the Pacific Ocean.
Where is new lithosphere is created?
New lithosphere is constantly being produced at the oceanic ridges. Lithosphere is consumed at the subduction zones. A balance is maintained because older, denser proportions of oceanic lithosphere descend into the mantle at a rate equal to seafloor production.
What is it called where tectonic plates meet?
Most volcanoes, mountains, and earthquakes occur where plates meet. Places where plates meet are called plate boundaries. There are seven major plates along with countless minor plates. You can see that a plate can be made of both oceanic crust and continental crust.
What occurs when two plates move together?
When two plates come together, it is known as a convergent boundary. Thus, at convergent boundaries, continental crust is created and oceanic crust is destroyed. Two plates sliding past each other forms a transform plate boundary.
What happens to the lithosphere when two plates move together?
If two tectonic plates collide, they form a convergent plate boundary. When two plates are moving away from each other, we call this a divergent plate boundary. Along these boundaries, magma rises from deep within the Earth and erupts to form new crust on the lithosphere.
What happens when 2 plates carrying continental crust collide?
When two plates with continental crust collide, they will crumple and fold the rock between them. A plate with older, denser oceanic crust will sink beneath another plate. The crust melts in the asthenosphere and is destroyed.
What happens when two plates slide or grind past each?
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.
What happens to the material of a plate that goes under nearby plates?
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. Plates include both oceanic crust and continental crust.
Why do older plates Subduct?
When two oceanic plates meet, the older plate subducts. Oceanic lithosphere is formed hot and thin at mid-ocean ridges and grows thick as more rock hardens underneath it. As it moves away from the ridge, it cools. Rocks shrink as they cool, so the plate becomes more dense and sits lower than younger, hotter plates.