Convergent Boundaries
There is nothing proving that the earth has gotten bigger over the years. So it is believed that the older crust is being recycled at the same pace the new crust is being made. The old crust is being recycled at at boundries where the plates move closer to eachother. The boundaries are called Convergent Boundaries. There are three types of convergent boundaries.
1.Oceanic-Continential
2. Oceanic-Oceanic
3. Continential-Continential
Certain types of plates comming together create the different boundaries.
1.Oceanic-Continential
2. Oceanic-Oceanic
3. Continential-Continential
Certain types of plates comming together create the different boundaries.
Oceanic-Continential Convergence
When a oceanic plate and continential plate meet, the oceanic plateslides under the continential plate. The place where the oceanic plate goes under a different plate and into the mantle is called a subduction zone. When subduction zones are along an oceanic- continential boundary they create deep sea trenches (long, skinny, deep cuts or indentations in the floor of the sea).
Oceanic- Oceanic Convergence
When two oceanic plates come in contact with eachother the older, colder, thicker plate curves and lovwer into the mantle. Like oceanic- continential convergence, oceanic- oceanic convergence make deep sea trenches.
Continential- Continential Convergence
When two continential plates collide they crumple up, this is how mountain ranges are formed. Often times earthquakes begin at places where continential plates meet. this happens because stress builds up between the two plates (because they are pushing and grinding against eachother) and finally the plates break and crumble. The force sends out sizemic waves, begining the earthquake.