Power law relationships: on a log-log plot, you get a straight line. Oodles of small ones occure though (i. e. lots and lots and lots) Determine this by: empirical observations, laboratory experiments, computer modeling. In general: the closer you are to the earthquake, the greater the damage, the greater the magnitude of the earthquake, the greater the damage. But, this can be modified by natural and anthropogenic conditions. Anthropogenic: nature of the structures that we build. Earthquake hazards: what exactly causes damage: surface faulting. Structures on the fault will be disrupted by the tearing motion: so don"t build right on active faults (but people do! Francisco, and other parts of the san andreas fault: ground shaking. This is generally the greatest threat to buildings and people. Sand soil (intermediate shaking) clay soil (most shaking) And, the most severe shaking is in the water-saturated clay soil. When seismic waves slow down as they go into another material.