| A | B |
|---|
| subduction zone | area where 2 plates are colliding and 1 plate is pushed under the other; ex. Marianas Trench |
| divergent boundaries | place where 2 plates separate; ex. Mid Ocean Ridge in the Atlantic Ocean, Great Rift Valley in Africa |
| convergent boundaries | place where 2 plates collide; ex. Himalayan Mountains |
| transform boundaries | place where 2 plates slide past one another; ex. San Andreas Fault, Ca. |
| convection current | circular movements in a material (like water or magma) caused by a hotter material rising and a cooler material sinking |
| Pangea | the supercontinent; 250 million years ago |
| Plates | Pieces of the crust (lithosphere) that float on the asthenosphere |
| Magma | molten rock below the surface of the earth |
| Continental Drift Theory | the idea that the Earth's plates are floating on the mantle and have been for millions of years |
| Trenches | the deepest places on the surface of the Earth; located at subduction zones; Marianas Trench is the deepest |
| Focus | the location of the earthquake underground |
| Epicenter | the surface above the focus; this is found through triangulation of seismic waves |
| p waves | seismic waves; very fast; travel like a slinky - they arrive first - primary |
| s waves | These seismic waves travel slower like a rope; they arrive after the primary waves; cannot travel through liquids |
| surface waves | travel in a circular manner only on the surface of the Earth; these are the most destructive seismic waves |
| lithosphere | the crust and rigid upper mantle; it is broken into plates |
| asthenosphere | upper, flowing mantle; moves plates by convection |
| core | made of iron and nickel; very hot due to radioactive elements |
| outer core | very hot due to melted elements; liquid! |
| inner core | hottest layer; solid due to pressure |
