It is pulled down along a fault line where two tectonic plates meet. If you are looking for a location there is a fault line right off the coast of California.
The oceanic crust slides under the continental crust due to the differences in their densities. The continental crust is more felsic (contains more silica) which makes it lighter than the oceanic crust which is more mafic (containes more fe and mg). Because the process of subduction is very slow, gravitational forces have a stronger effect on the more dense oceanic crust, causing this crust to be pulled under the continental crust and down into the mantle.
deep ocean trench.
The continental shelf is normally made out of continental crust, the oceanic crust begins at the base of the continental rise. However in most places the oceanic crust near the continental margins is covered by continental sediments (eroded form the continents) carried down onto the Oceanic planes by deep sea canyons running off the continental rises.
Subduction occurs on continental boundaries because oceanic sub floor is denser and heavier than the lighter more buoyant crust. The oceanic crust slides under the continental crust areas usually on a plate boundary. This is in a recycle style mode that constantly is remaking the ocean floor. The oldest rocks on the ocean bottom are a drop in the geologic time bucket, compared to the rock ages on land.
Oceanic crust isn't destroyed because it's old; it is, in fact, destroyed due to destructive plate boundaries. This is where a continental plate and an oceanic plate move towards each other. As the oceanic crust is denser, it is pushed under the continental plate. Here it is forced into the mantle of the earth, where it is destroyed due to heat and convection currents.
New crust is formed on the opposite end of the plate as it is pulled away from its neighbor.
the oceanic crust slides down and burns in the mantle and forms a volcano
The plate with cooler, denser crust sinks under the other plate, forming a trench. There, the oceanic crust sinks down back into the mantle.
The plate with cooler, denser crust sinks under the other plate, forming a trench. There, the oceanic crust sinks down back into the mantle.
Continental crust, on average, is much thicker than oceanic crust. Because of the principles of isostacy and buoyancy, the continental crust will protrude more deeply into the asthenosphere than oceanic crust.
The oceanic crust slides under the continental crust due to the differences in their densities. The continental crust is more felsic (contains more silica) which makes it lighter than the oceanic crust which is more mafic (containes more fe and mg). Because the process of subduction is very slow, gravitational forces have a stronger effect on the more dense oceanic crust, causing this crust to be pulled under the continental crust and down into the mantle.
deep ocean trench.
deep ocean trench.
The oceanic crust is force down into the mantle in a process called subduction. The subducting oceanic plate will introduce water into the hot mantle, causing some of the rock to melt. The molten rock will rise through the overriding continental crust to form volcanoes.
The crust goes down about 10 kilometers. Continental crust is about 3 billion years old and oceanic crust is about 70-100 million years old.
At the opposite end of the convection current in the Earth's mantle that creates oceanic crust at the mid-ocean ridge, are trenches, where oceanic crust is diving down into the mantle. The Atlantic Ocean is expanding. The Pacific Ocean is shrinking.
The continental shelf is normally made out of continental crust, the oceanic crust begins at the base of the continental rise. However in most places the oceanic crust near the continental margins is covered by continental sediments (eroded form the continents) carried down onto the Oceanic planes by deep sea canyons running off the continental rises.