| A | B |
|---|
| plate boundary | where two tectonic plates are in contact |
| divergent plates | plates that spread appart |
| converging plates | plates that collide |
| trench | where a oceanic plate slides beneath a continental plate |
| volcanic belt | long chain of volcanoes |
| oceanic-oceanic convergence | form a volcanic island |
| continental-continental convergence | form high mountains: Himalayas |
| transform plate boundaries | tectonic plates that slide past each other |
| transform plate boundaries form | faults |
| earthquake | release of energy that shakes the crust |
| focus (foci) | location inside the earth where the earthquake occurs |
| epicentre | point on the earth suface above the focus |
| seismology | study of earthquakes and sismic waves |
| types of seismic waves | surface (L), primary (P) and secondary (S) |
| surface waves (L) | slowest waves. Through surface |
| primary waves (P) | 6 km/. Fastest waves. Through solids, liquids and gases |
| secondary waves (S) or shear waves | 3.5 km/h. Cause move damage. |
| seismometers or seismographs | used to measure ground movement |
| magnitude of an earthquake | number that indicates the strenght or energy of an earthquake |
| types of volcanoes | shield v., composite v. |
| composite volcanoes | large cone shaped mountains |
| shield volcanoe | formed over hot spots. Less explosive than composite v. |
| rift eruptions | when magma flows through long cracks |
