Reducing Uncertainty in Ground Motion Models

Characterization of earthquake ground motion for engineering applications varies from place to place, and the degree of variability, which depends on the application and on the place, is not always intuitive. One would expect, for example, that parts of the globe with frequent earthquakes and dense strong-motion networks (e.g., areas with rich ground motion datasets, such as California) would have developed ground motion models with lower uncertainty than the other parts of the world, where moderate and large earthquakes occur infrequently, and monitoring networks are sparse or have a short history of use. Following that line of thought, one can also expect that stakeholders in metropolitan areas, where seismic networks are more dense than in rural regions, would be able to use the additional ground motion data to refine the ground motion models around these metropolitan areas and reduce the uncertainty further.