Bell Work: September 3 Define The Plate Tectonic Theory What are some ways that plate tectonics change the surface of the earth?

Plate movement As plates move, they collide, pull apart, or grind past each other. This changes Earth’s surface including volcanoes, mountain ranges, and deep-ocean trenches.

Plate Boundaries There are three kinds of plate boundaries: 1. Divergent 2. Convergent Transform

Divergent Boundaries When plates move apart, or diverge. Most occur along the mid-ocean ridges. On land, divergent boundaries form rift valleys. Example: The Great Rift Valley in East Africa

Convergent Boundaries Where plates come together or converge. This is called a collision The density determines which one comes out on top. May form trenches, volcanoes, mountains, subduction zones Oceanic-Oceanic: the most dense plate sinks under the other forming a trench. Example: Mariana Trench Oceanic-Continental: Oceanic crust is more dense and sinks below the continental plate as subduction.

Convergent Boundaries Continental-Continental: Neither sinks, but squeezes into mountain ranges. Example: Himalayas

Transform Boundaries Where two plates slide past each other in opposite directions. Earthquakes occur. Examples: The San Andreas Fault

Plate Map Map the movement of the plates. What do the arrows show? Create a map key.

Divergent Convergent TransformP. 151

Homework Find a creative way to represent different plate boundary movements. What can you use, or how can you show plate boundaries? Examples: Drawing, model, etc.