Implements GMPE developed by Arthur Frankel et al. and documented in “National Seismic-Hazard Maps: Documentation June 1996” (USGS - Open File Report 96-532) available at: http://earthquake.usgs.gov/hazards/products/conterminous/1996/documentation/ofr96-532.pdf
The GMPE is used by the National Seismic Hazard Mapping Project (NSHMP) for the 2008 central and eastern US hazard model.
This class replicates the algorithm as implemented in subroutine getFEA in the hazgridXnga2.f Fortran code available at: http://earthquake.usgs.gov/hazards/products/conterminous/2008/software/
The GMPE is defined by a set of lookup tables (see Appendix A) defined from minimum magnitude Mw=4.4 to maximum magnitude Mw=8.2, and from (hypocentral) distance 10 km to 1000 km. Values outside these range are clipped.
Lookup tables are defined for PGA, and SA at the following periods: 0.1, 0.2, 0.3, 0.5, 1.0, 2.0. The GMPE does not allow for interpolation on unsupported periods.
The class assumes rupture magnitude to be in Mblg scale (given that MFDs for central and eastern US are given in this scale). However lookup tables are defined for Mw. Therefore Mblg is converted to Mw by using Atkinson and Boore 1987 conversion equation.
Coefficients are given for the B/C site conditions.
Supported intensity measure component is the geometric mean of attr:~openquake.hazardlib.const.IMC.AVERAGE_HORIZONTAL,
Supported intensity measure types are spectral acceleration, and peak ground acceleration
Supported standard deviation type is only total.
Supported tectonic region type is stable continental crust, given that the equations have been derived for central and eastern north America
Required distance measure is rhypo
Required rupture parameter is only magnitude (Mblg).
No site parameters required
Extend FrankelEtAl1996MblgAB1987NSHMP2008 but uses Johnston 1996 equation for converting from Mblg to Mw.