Mod+5.6+-+Marisa+Y

Dynamic Earth

Convergent Boundaries
 * When a plate collides with or dives under another plate.
 * Can happen with continental or ocean plate.
 * Subduction is when a ocean plate dives under a landmass.
 * Indian Plate and Eurasian Plate collided about 55 million years ago to form Himalayas.


 * Mountains form when two continental plates collide.
 * When South America collided with the Nazca Plate they formed the Andes Mountains.
 * An Ocean-Ocean subduction caused the Island of Indonesia.
 * When two ocean plates collide they form trenches.
 * A famous trench is the Mariana Trench in the North Pacific Ocean.
 * These collisions can also cause underwater volcanos which form island acres like Japan.

__Divergent Boundaires__


 * When magma rises to the Earth's surface and pushes two plates apart.


 * This process can renew ocean floors and widen basins.
 * Divergent Boundaries along the Mid Atlantic ridge cause the Atlantic to widen 2 centimeters per year.
 * Ridges formed by this are usually 30-50 Kilometers wide.
 * East Africa Rift in Kenya and Ethiopia, also the Rio Grande Rift in New Mexico are great examples.
 * These Divergent Boundaries can cause Volcanic and Earthquake activity.

Transform Boundaries


 * When plates slide past each other and grind against each other.
 * The San Andreas Fault was formed when the Pacific Plate slide past North America.
 * Due to this the San Andreas Fault is moving north while California is moving south.
 * The fault will not crack off,but move upward and in 10 million years San Francisco will be side by side with Los Angelous.[[image:sanandreasfault1.jpg width="248" height="375" caption="San Andreas Fault in California"]]
 * Transform Boundaries cause very powerful Earthquakes.
 * These also cause fracture zones along mid-ocean ridges.

"Plate Tectonics." //National Geographic//. N.P., n.d. Web. 10 Nov. 2009. .
 * __Bibliography__**