| A | B |
|---|
| convergent plates | tectonic plates moving towards each other |
| divergent plates | tectonic plates moving away from each other |
| sliding plates | tectonic plates sliding past each other |
| 4-40 miles thick | crust |
| molten rock layer | mantle |
| liquid iron 1300miles thick | outer core |
| solid iron, 1500 miles thick | inner core |
| rigid, outer shell of earth | lithosphere |
| base of crust defined seismologically | Mohorovic discontinuity (Moho) |
| behaves as a highly viscous fluid | asthenosphere |
| compositional layering | crust, mantle,Moho, inner core, outer core |
| mechanical layering | lithosphere, asthenosphere |
| seafloor spreading | a divergent zone |
| subduction | a convergent zone |
| hot spots | thinner, weaker "spots" where magma reaches the earth's surface |
