The probability that social or economic consequences of earthquakes will equal or exceed specified values at a site, at several sites, or in an area, during a specified exposure time. Historically the term seismic risk has been used to describe an assortment of earthquake effects that range from ground shaking, surface faulting, and earthquake-induced landsliding to economic loss and casualties. As more quantitative methods for estimating the effects of earthquakes have been developed, terminology has become more precise. Although the term seismic risk is still sometimes used in a general sense to mean the potential for both the occurrence of natural phenomena and the economic and life loss associated with earthquakes, it is useful to differentiate between the concepts of seismic hazard and seismic risk. Seismic hazard may be defined as any physical phenomena (for example, ground shaking or ground failure) that are associated with an earthquake and that may produce adverse effects on human activities.