Seismic waves Flashcards
1
Q
Primary waves
A
Fastest - compressional vibrating in the direction they travel
2
Q
Secondary waves
A
Half the speed of P-waves and shear rock by vibrating at right angles to the direction of travel
3
Q
Surface waves
A
Travel slowest and near to ground surface. Some shake the ground at right angles to the direction of wave movement. Some have a rolling motion that produces vertical ground movement
4
Q
How do they cause earthquakes?
A
When plates jerk past each other due to tension seismic waves (vibrations) are sent out. These vibrations are the eathquake
5
Q
Where do they spread out from
A
The focus
