| A | B |
|---|
| Alfred Wegener | He hypothesized that all the continents had once been joined into a supercontinent |
| Pangaea | The name of the supercontinent |
| Continental drift | Wegener's theory that the continents slowly move across the Earth's surface |
| Mesosaurus | A freshwater reptile that Wegener used as fossil evidence for continental drift |
| Glossopteris | An ancient plant found on widely separated continents. Provides evidence of continental drift. |
| Mid ocean ridge | The underwater mountain chain where new sea floor is made. |
| Sonar | This was used by Hess to make maps of the ocean floor. |
| Sea floor spreading | The process by which molten material adds new oceanic crust to the ocean floor |
| Harry Hess | Built on Wegener's ideas and proposed the theory of sea-floor spreading |
| Basalt | Lava rocks that made up the mid-ocean ridge |
| Magnetic stripes | Patterns in the sea floor that show reversals of the Earth's magnetic field; used as evidence for sea-floor spreading |
| Drilling samples | Rocks taken from both sides of the mid-ocean ridge have the same age and pattern; the oldest ones are further from the ridge |
| trench | An underwater canyon formed from subduction |
| Subduction | The process by which oceanic crust sinks back into the mantle |
| Plate | A piece of the lithosphere that includes pieces of continental and oceanic crust |
| Ring of Fire | The major earthquake and volcano zone located in the Pacific Ocean |
| Plate tectonics | The theory that pieces of the Earth's lithosphere are in constant motion |
| Transform boundary | A plate boundary where two plates slide past each other in opposite directions |
| Convection currents | These cause the Earth's plates to move |
| Divergent boundary | A plate boundary where two plates are spreading apart |
| Rift valley | A deep valley that forms where two plates move apart at a divergent boundary |
| Convergent boundary | A plate boundary where two plates are colliding |
| Andes Mountains | A real world example of an oceanic-continental convergent boundary |
| Japan | A real world example of an island arc |
| island arc | This is created at an oceanic-oceanic convergent boundary |
| Himalayas | A real world example of a continental-continental convergent boundary |
| Pacific | This ocean that is shrinking because there is so much subduction and very little sea-floor spreading |
| Atlantic | The ocean that is expanding because there is so little subduction and so much sea-floor spreading |
| Spitsbergen | An island near the north pole where Wegener found tropical plant fossils |
| Glacier scratches | Marks found in Africa, India, and Australia that indicated to Wegener that those places used to be cold! |
| Coal fields | Land features used by Wegener that matched up in North America and Europe |
| J Tuzo Wilson | The scientist who put together the Theory of Plate Tectonics |
| San Andreas Fault | A real world example of a transform boundary |
