Home » Shop » 2014 – Earthquake recurrence models for seismic hazard assessments
Gary Gibson and Vicki-Ann Dimas
Earthquake recurrence models are based on observed seismicity, geological data and geodetic motion. They are particularly difficult to define in regions of low seismicity where the average recurrence interval between moderate to large earthquakes greatly exceeds the duration of the known earthquake catalogue.
The earthquake process may be considered as ongoing long-term deformation due to plate movement in the region about the fault, resulting in stress build-up, and a significant number of small earthquakes through the deformed region. Larger earthquakes occur at irregular intervals, with ruptures on the larger faults that release elastic strain energy from the region. Most strain energy release is during the large fault rupture.
This gives a wider range in hazard estimates compared with extrapolation methods, increasing hazard in regions of active faulting and reducing hazard where long-term geological stability can be observed. As dams are usually in regions with recent uplift, this method will tend to increase hazard estimates.
ANCOLD is an incorporated voluntary association of organisations and individual professionals with an interest in dams in Australia.