These are seen as mountains formed from volcanoes. Plate movements cause push and pull stresses in the crust that are relieved by sudden breaks along faults. Movement along faults causes earthquakes, the sudden shaking of the ground, as energy is released in the form of seismic waves traveling outward from the earthquake source. Fault movement can be predominantly vertical or predominantly horizontal. Vertical movement occurs when a mountain block moves upward relative to the valley block moving downward.
Horizontal movement occurs when blocks shift laterally or sideways.
The majority of faults and earthquakes are found at plate boundaries. Earthquakes occur when pressure that has built up in the earth is suddenly released in the form of seismic waves and mass Earth movement. Scientists can measure the magnitude of an earthquake by using the Richter Scale , which measures the size and the energy of the waves. The Richter Scale measures the amplitude, or height of the waves. The Richter Scale can be used to predict the amount of damage that might occur during an earthquake.