| A | B |
|---|
| Seismic waves | Most of the time caused by eathquakes. They travel through the earth. |
| Body waves | Body waves travel through the inner earth. Body waves are divided into two groups; P waves (primary waves) and S waves (secondary waves). |
| P waves | P waves are longitudal waves. They travel a little less than twice the speed of S waves, or the speed of sound. |
| Primary waves | P waves |
| S waves | S waves can't travel throuh liquids, only solids. They are sometimes calles secondary waves. |
| Secondary waves | S waves |
| Love waves | Surface waves that cause horizontal shearing in the ground. They were discovered by A.E.H. Love in 1911. They move slower than p and s waves |
| Crest | The highest point on a wave. |
| Trough | The lowest point on a wave. |
| Reflection | wave change in direction change from hitting a reflective surface |
| Refraction | wave change in direction from entering a new medium |
| Diffraction | wave circular spreading from entering a hole of comparable size to their wavelength. |
| Constructive interference | When two waves collide, their crests add to each other and make a larger wave |
| Destructive interference | When two waves collide, a crest and trough combine, canceling each other out. |
| Wavelength | The distance from one point on a wave, to the second place where that point is repeated (crest to crest, or trough to trough), usually measured in some form of meters |
| Frequency | How many waves pass a given point in a given time (usually one second) |
| Period | The time for one complete cycle for an oscillation of a wave |
| Hertz | The units for frequency (cycles per second) |
| Speed of a wave through a vibrating string | Speed of a wave through a string (v) = the square root of (the string tension (T) divided by the linear density (mu)) |
| Doppler Effect | The change in frequency of an object in motion. A police car sounds higher as it move toward you, and lower as it moves away. |
