Plate Boundaries

Divergent, Convergent, and Transform

Divergent Plate Boundaries:

  Divergent plate boundaries are plates that move away from each other. They often create rifts and eventually turn into rift valleys. They occur between oceanic crusts and exist as mid-oceanic ridges.

  Divergent plates also form volcanic islands. When divergent plates move apart, they produce lava or magma from below and fills the gap above. Therefore, divergent plates are where oceanic/mid-oceanic crusts are.

   Some famous divergent plate boundaries are located are the East African Rift System, the Rio Grande rift, the Mid-Atlantic Ridge, and the East Pacific Rise. Also, the Mid-Atlantic Ridge causes the Atlantic Ocean to widen at only about 2 centimeters per year.

Convergent Plate Boundaries:

  Convergent plate boundaries are when two plates collide and cause mountains or volcanoes. Because of the pressure and friction these land features occur. They form subduction zones near oceanic crust.

  With these underwater earthquakes, tsunamis happen, too. When two plates collide, they form trenches, and melted rocks rise up and form more earthquakes.

   It is somewhat dangerous to live near convergent boundary plates, but with preparation and alertness it is possible to live near these plate boundaries. Some famous mountains caused by convergent plate boundaries are the Rockies, Alps, Mt. Everest, Himalayas, and the Pontic Mountains. Mount Vesuvius at Italy in A.D. 79 killed about 16,000 people.

Transform Plate Boundaries:

   Transform plate boundaries are when two plates slide past each other. They often cause earthquakes, but don`t create or destroy the lithosphere. These boundaries are commonly found linking the segments of the mid-oceanic ridges.

   The most famous and strong transform plate is the San Andreas fault. In 1906, the earthquake near the fault hit San Francisco and killed 600 people. The slice of California to the west is slowly moving north with the rest of California. So, Los Angeles will not float away, but move next to San Francisco at about 6 centimeters a year. In about ten million years, the two cities will be side by side!

This is a map of the tectonic plates covering the earth:

Sound tracks you can listen to: