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Dynamic Earth

Convergent Boundaries Convergent boundaries occur when two plates collide. If these two plates serve as a landmass one of the plates will slide on top of the other. The result creates mountains. For example, 55 million years ago, plates in Asia and India crashed, starting the Himalayas (mountain rrange)which extend nearly 1600 miles. The most famous mountain in the himalayas is Mount Everest. When plates in the ocean go under land masses, called subduction, a trench will form like the Mariana Trench. The Mariana Trench was formed in the North Pacific Ocean.

Divergent Boundaries Divergent boundaries form when plates move apart. Magma rising from the mantle pushes the two plates away. If a divergent boundary is formed in the ocean a crevice will form. In the crevice underwater volcanoes and mountains will form. If the plates move under a land mass, a valley will form. One of the most famous valleys is the Great Rift Valley in Africa.

Transform Boundaries Transform boundaries are when plates grind against each other. Another name for this is strike-slip faults. When plates grind against each other earthquakes are triggered. 80% of earthquakes occur along the rim of the Pacific Ocean, or the "Ring of Fire". 10,000 people die annually from earthquakes. Transform boundaries also cause faults. One of the most well known faults is the San Andreas Fault.