Rift+Valley

=Rift Valley !=
 * ** : ** In the diagram below you can see that the continental crust is beginning to separate creating a **diverging** plate boundary. When a divergence occurs within a continent it is called rifting. A [|plume] of hot magma rises from deep within the mantle pushing up the crust and causing pressure forcing the continent to break and separate. Lava flows and earthquakes would be seen. In the diagram below you can see that the continental crust is beginning to separate creating a **diverging** plate boundary. When a divergence occurs within a continent it is called rifting. A [|plume] of hot magma rises from deep within the mantle pushing up the crust and causing pressure forcing the continent to break and separate. Lava flows and earthquakes would be seen. ||


 * [[image:http://www.moorlandschool.co.uk/earth/images/divergeplates.gif width="296" height="96" caption="diverge plates animation.gif (16916 bytes)"]] || This is an example of a divergent plate boundary (where the plates move away from each other). The Atlantic Ocean was created by this process. The mid-Atlantic Ridge is an area where new sea floor is being created. ||


 * [[image:http://www.moorlandschool.co.uk/earth/images/diverge_plates.gif width="299" height="110" caption="diverge plates with opening rift valley animation.gif (18569 bytes)"]] || As the rift valley expands two continental plates have been constructed from the original one. The molten rock continues to push the crust apart creating new crust as it does. ||


 * [[image:http://www.moorlandschool.co.uk/earth/images/widening_ocean.gif width="298" height="89" caption="diverge3 animation widening ocean.gif (17635 bytes)"]] || As the rift valley expands, water collects forming a sea. The Mid-Atlantic Ridge is now 2,000 metres above the adjacent sea floor, which is at a depth of about 6,000 metres below sea level. ||


 * [[image:http://www.moorlandschool.co.uk/earth/earth_science/diverge4_animated_sequence.gif width="408" height="130" caption="diverge4 animated sequence.gif (25011 bytes)"]] || The sea floor continues to spread and the plates get bigger and bigger. This process can be seen all over the world and produces about 17 square kilometres of new plate every year. ||