* Continents are made of continental crust: This crust is thicker and less dense than oceanic crust. It doesn't easily subduct (slide) under other plates.
* Subduction zones: Most new crust is formed at mid-ocean ridges where plates pull apart and magma rises. However, when oceanic plates collide with continental plates, the denser oceanic plate subducts under the continental plate. This process doesn't add to the continent, it recycles the oceanic crust.
* Continental collisions: When continents collide, they can create mountains like the Himalayas. This isn't "growth" in the sense of adding new land, but rather the deformation and uplift of existing land.
So how do continents change?
* Erosion and deposition: Weathering and erosion break down rocks on land, and these sediments are transported by rivers and oceans. This material can build up on continental margins, adding to the landmass over very long periods.
* Volcanic activity: Volcanoes can add new land, especially in areas where the continental crust is thin. This can be seen in Iceland, where volcanic activity is building up the island.
In summary:
While plate tectonics is the driving force behind many geological processes, it doesn't directly cause continents to grow in terms of adding new landmass. Instead, continents change through processes like erosion and deposition, and sometimes volcanic activity.
