Module 7: Plate Tectonics and Earth's Structure
Just a century ago, scientists believed that the Earth’s interior was solid and that the locations of the continents and oceans were fixed in place. Due to advances in technology and new evidence, scientists today know that the Earth’s interior is structured in layers that are still cooling from the time of formation, more than 4.5 billion years ago. Scientists have discovered evidence that Earth’s solid crust is divided into several major plates. These plates slowly shift and move on top of the uppermost molten layer of the Earth. Scientists believe that continents move towards and away from each other at about the rate your fingernails grow. New crust is created at the ocean floor where the plates move apart and mountain ranges grow as plates collide. The change is slow but constant. The movement triggers creates large scale tectonic activity at Earth’s surface in the form of volcanoes and earthquakes.
In this module, you will learn about the structure of Earth’s interior and how it drives the movement of Earth’s solid crust. You will explore the theory of plate tectonics, the different ways the plates move and interact with each other, and the landforms they create. You will also learn what causes earthquakes and volcanoes, and how they impact life on Earth’s crust.
Getting Started
Scientists believe that plate tectonics is a driving force in earth quakes and volcanoes. In this non-graded activity, drag and drop the pieces of the puzzle to create a picture of the Haleakala Volcano in Maui, Hawaii. Click SUBMIT once you have completed the puzzle. Click the player button to get started. Good luck!
Key Vocabulary
To view the definitions for these key vocabulary terms, visit the course glossary.
| active volcano | hot spot | rift valley |
| Alfred Wegener | inner core | Ring of Fire |
| asthenosphere | laccolith | seafloor spreading |
| cinder cone volcano | lithosphere | secondary wave |
| composite volcano | magma chamber | seismogram |
| continental collision | mantle | seismometer |
| continental drift | mid-ocean ridge | shield volcano |
| convection | Modified Mercalli Intensity Scale | sill |
| convergent boundary | Mohorovicic discontinuity | strike-slip fault |
| crater | normal fault | subduction |
| dike | ocean trench | surface wave |
| divergent boundary | outer core | transform boundary |
| dormant volcano | parasitic cone | triangulation |
| epicenter | plasticity | tsunami |
| extinct volcano | plate tectonics | vent |
| fissure | pluton | viscosity |
| focus | primary wave | volcanic island arc |
| fumarole | pyroclastic material | volcanic mountain range |
| Gondwanaland | reverse fault | volcanologist |
| Harry Hess | Richter Scale |