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__** Boundaries of Dynamic Earth **__

When a plate collides with or divides under another plate, it is called a **Convergent Boundary**. Convergent Boundaries form things such as mountain ranges. For example, due to Convergent Boundaries, the India and Asia plates crashed about fifty-five million years ago, slowly creating the Himalayas. The plates responsible are the Eurasian Plate and the Indian Plate. Another example is Mount Everest. Mount Everest grows 1/4 of an inch taller every year due to these boundaries. Convergent Boundaries also occur where a plate of ocean dives, called subduction, under a landmass, which is over-all called ocean-continent. One more example is the Andes Mountains. The Nazca plate was subducted under the South American plate to form these mountains.



When magma rises and pushes plates apart under an ocean or continent, it is called a **Divergent Boundary**. Divergent Boundaries form things such as mountains and volcanos along the seam of continents and oceans. An example of this is The Great Rift Valley. If the plates continue to diverge, millions of years from now Eastern Africa will split from the continent to form a new landmass. The African Plate and the Somali Plate are the plates responsible for the valley. When Divergent Boundaries occur in the ocean, magma is pushed through the oceanic crust and creates a new sea-floor. An example of this process is The Deep Drift Valley which is caused by the mid-ocean ridge plate.





When two plates grind against eachother, it is called a **Transform Boundary** (also known as the eighth grade dance move). Transform Boundaries don't form mountains or volcanos, but they do trigger large earthquakes. An example of a transform boundary is The San Andreas Fault in California. The San Andreas Fault is the biggest fault in California. The plates responsible are named North American Plate and the Juan de Fuca Plate. It was formed when the Pacific Plate(on the west) moved northwestward, relative to the North American plate(on the east), causing earthquakes along the fault. An example of Transform Boundaries in oceans is still The San Andreas Fault because vibrations due to the plates can be built in the oceans, leading to the fault.





Citations:

"Earthquakes: The Prehistoric Record." //Teachers Domain//. 2002. Web. 1 Jan. 2009. [].

Howel, Paul. "Future Animation." //Paleomap Project//. n.p., n.p. Web. 18 Nov. 2009. [].

"Plate Tectonics." //Earth Science//. n.p., n.p. Web. 18 Nov. 2009. [].

"Plate Tectonics." //National Geographic//. National Geographic, Web. 13 Nov. 2009. [[[]