When earthquake intensity we discussed some of the basic factors that affect the amplitude and duration of shaking produced by an earthquake and as you are aware, the shaking caused by seismic waves can cause damage buildings or cause buildings to collapse. The level of damage done to a structure depends on the amplitude and the duration of shaking. The amplitudes are largest close to large earthquakes and the duration generally increases with the size of the earthquake (larger quakes shake longer because they rupture larger areas).