| A | B |
|---|
| Mantle | thickest layer of earth made of hot rock |
| outer core | layer of earth made of liquid metal |
| inner core | layer of earth made of solid metal |
| crust | layer of earth where sudden shifts cause earthquakes |
| heat transfer | movement of energy from warmer object to cooler one |
| radiation | transfer of heat through open space |
| convection | transfer of heat through direct contact of objects |
| conduction | transfer of heat by movement of heated fluid |
| convection currents | flow that transfers heat through a fluid |
| asthenosphere | where convection currents are located in the mantle |
| Pangaea | Alfred Wegener's super-continent |
| mid-ocean ridge | where molten material rises from the mantle and erupts |
| Sea-Floor Spreading | Harry Hess's radical idea about the ocean floor |
| plates | seperate sections of the lithosphere |
| faults | breaks in Earth's crust where rocks slip by one another |
| transform boundary | two plates slip by each other in opposite directions |
| divergent boundary | two plates move apart, or diverge |
| convergent boundary | two plates move towards each other, or converge |
| rift valley | deep valley that forms along a divergent boundary on land |
| earthquake | shaking and trembling from rocks moving beneath Earth's crust |
| seismic waves | vibrations that travel through Earth carrying energy released during an earthquake |
| aftershock | earthquake that follows a much larger earthquake |
| tsunami | large wave formed by water displaced by an earthquake |
| magma | what lava is called before it reaches Earth's surface |
| active volcano | a volcano that will erupt in the near future |
| extinct volcano | a volcano that will probably never erupt again |
| dormant volcano | a volcano that may erupt in the distant future |
| igneous rocks | a type of rocks found near volcanoes |
