| Term | Definition |
| a German scientist in the early 1900's. other scientists thought his ideas were crazy, he travelled looking for fossil and rock clues | who is Alfred Wegener? |
| he was the first to discover continental drift and plate tectonics, he thought that all of the continents had been together at one point but they broke apart and the pieces drifted to their present positions | what did Alfred Wegener believe about the earth? |
| supercontinent that existed 250 million years ago | what was pangea? |
| existed in the Palaozoic and Mesozoic eras 250 million years ago | how long ago did pangea exist? |
| same plant fossils, animal fossils, and rock deposits on different continents this means that they were once joined with pangea | what supported Wegener's theory? |
| when the ocean floor is extended by plates moving apart | what is seafloor spreading? |
| volcanoes along the plate boundaries? | what can seafloor spreading cause? |
| seafloor spreading wasn't discovered untill the invention of the submarine | why was seafloor spreading only discovered in the 1960's? |
| large rock that ride on top of the asthenosphere that make up thhe earth's crust and continents | what are tectonic plates? |
| 10, along with other minor ones | how many major tectonic plates are there? |
| any sudden movement | what plate movement causes an earthquake? |
| subduction, when a plate goes under another plate | what plate movement causes a tsunami? |
| divergent, when plates pull apart | what plate movement causes a valley? |
| convergent, when plates crash together and buckle and rise up | what plate movement causes a mountain? |