In some regions the plates scrape and grind past one another. In other areas, known as divergence zones , the plates are spreading apart. When plates spread, lava rises, forming new oceanic crust. The only location where this process is not covered by an ocean is Iceland. This tiny island nation is being pulled apart as molten rock rises from deep within the Earth to keep the island growing.
Plates crash together at convergence zones .
If both plates are continental, the land is pushed up, generating enormous mountains like the Himalayas, the world's highest mountain range. If an oceanic plate meets a continental plate, the denser oceanic plate dives beneath the more buoyant, lighter, continental plate. The zone where these plates meet forms a deep trench and above the subducted oceanic plate lies a string of stratovolcanoes. Plate tectonic interactions along the Pacific Ring of Fire. Almost all of the Pacific ocean lies on a single plate, the Pacific plate.