Probabilistic earthquake hazard computations is done, using the EQRISK program [McGuire, 1976] or the CRISIS2012 program [Ordaz, 1991,1999].
EQRISK computes seismic hazard in terms of probabilities of exceedence vs earthquake
intensity measures such as peak ground acceleration (PGA), for a given site or a grid of
sites for up to eight different return periods. The site amplification is calculated with
the SPEC program. This is used for making spectra of many seismic signals in a semiautomatic
manner. The program is intended for two purposes: (1) making relative spectra for a
series of pairs of stations terminated by the average spectra, (2) Making a series of
spectra for a number of stations and events. The spectra can be corrected for
distance, q, and instrument response.
This section involves a large number of programs and a more detailed description is given in section 33.