This is known as a trench in a subduction zone.
Its either a subduction zone or a rift valley.
A deep sea or ocean trench
Trenches.
A deep ocean subduction trench
It is called subduction and only occurs in oceanic to oceanic or oceanic to continental plate collisions.
Via currents of heated rock in the mantle which rise toward the surface. Very slowly.
It is an example of heat transfer by convection. Material heated by the outer core slowly moves toward the surface through the solid but plastically-mobile mantle.
Subduction occurs at convergent plate margins where plates are moving toward each other. Subduction occurs as old oceanic crust becomes thicker and more dense than the upper mantle directly below it. Because it is more dense, it is forced under younger, less dense oceanic crust, or under continental crust, which is always less dense. At these borders of collision, the older and more dense oceanic crust is drawn by gravity downward, into the mantle, where it is slowly melted. The two basic forces responsible are gravity and heat.
A deep ocean subduction trench
It is called subduction and only occurs in oceanic to oceanic or oceanic to continental plate collisions.
deep ocean trench.
gravity
Subduction is a result of a collision between two tectonic plates, either oceanic to oceanic collision or oceanic to continental plate collision. The heavier, or more dense plate sinks under the more buoyant less dense plate, and is drawn down into the upper mantle.
The convergence creates a trench where the more dense of the two plates flows downward toward the mantle. Earthquakes may occur in the area of the plate boundary, as well as volcanism.
New crust is formed on the opposite end of the plate as it is pulled away from its neighbor
Via currents of heated rock in the mantle which rise toward the surface. Very slowly.
It is an example of heat transfer by convection. Material heated by the outer core slowly moves toward the surface through the solid but plastically-mobile mantle.
When an oceanic to oceanic happens, two oceanic plates converge and one of the plates subducts into a trench. The subducted plate sinks down into the mantle and begins to melt. Molten rock from the plate rises toward the surface and forms a chain of volcanic islands, also called a volcanic island arc, behind the trench in the ocean.
Subduction occurs at convergent plate margins where plates are moving toward each other. Subduction occurs as old oceanic crust becomes thicker and more dense than the upper mantle directly below it. Because it is more dense, it is forced under younger, less dense oceanic crust, or under continental crust, which is always less dense. At these borders of collision, the older and more dense oceanic crust is drawn by gravity downward, into the mantle, where it is slowly melted. The two basic forces responsible are gravity and heat.
The ocean is never pulled under the continent. Oceanic crust--the rock and some sediments, however, slide under the edges of continental crust and are pushed downward toward the mantle in areas of oceanic to continental plate collisions.