There are two principal approaches of seismic hazard assessment: deterministic and probabilistic seismic hazard assessment. Both approaches are based on geological and seismological data, but the definitions of seismic hazard are fundamentally different. In the deterministic approach one or a few ‘controlling earthquakes’ are defined, for which the expected ground motion at a particular location is then determined. EFEHR provides models and results of a probabilistic approach, in which all earthquakes that may affect a given location are considered together with various possible models of ground shaking, in a statistical framework.
To assess seismic hazard with a probabilistic approach, scientists try to envision and model when, where and with what magnitude earthquakes will occur and how the ground shaking caused by these earthquakes can be described. This is done based on available datasets and information, scientific knowledge and research results. Therefore, seismic hazard assessments need to be regularly reviewed and updated.
EFEHR provides access to probabilistic estimates of future ground shaking, which take into account various approaches to model future earthquake occurrence and seismic wave propagation, for different regional hazard models.