HR: 1340h
AN: S53B-1110    [Abstracts]
TI: A Clear Definition of Seismic Hazard and Risk: A Basis for Hazard and Risk Assessment, Communication, and Management
AU: * Wang, Z
EM: zmwang@uky.edu
AF: Kentucky Geological Survey, 228 Mining and Mineral Resources Building, University of Kentucky, Lexington, KY 40506 United States
AB: Seismic hazards are the intrinsic natural occurrence of earthquakes and the resulting ground motion and other effects. A relationship between hazards and their occurrence frequency can be derived through a process called seismic hazard analysis. The main purpose of seismic hazard analysis is to provide parameters for estimating seismic risk. For example, probabilistic seismic hazard analysis (PSHA), a widely used method for deriving the relationship between ground-motion values and their annual probabilities of exceedance (or return periods), has been used to estimate seismic risk. Different seismic hazard analyses will provide different relationships, however. Risk also has different meanings among different professions, although it can be generally quantified by three terms: probability, hazard (loss or other measurements), and time exposure. In seismology, risk may be defined as the probability of earthquakes with a certain magnitude or greater striking at least once in a region during a specific period. In earthquake engineering, risk was originally defined as the probability that ground motion at a site of interest exceeds a specific level (hazard) at least once in a period (for example ground motion with 2 percent probability of exceedance in 50 years. These definitions of seismic risk have become a definition of seismic hazard, however. Because many different definitions of hazard and risk can be used, the resulting estimates of seismic hazard and risk can differ dramatically. Hence, a clear definition of seismic hazard and risk is needed in hazard and risk assessment, communication, and management.
DE: 7212 Earthquake ground motions and engineering seismology
SC: Seismology [S]
MN: Fall Meeting 2005