Implements GMPE developed by P. Somerville, N. Collins, N. Abrahamson, R. Graves, and C. Saika and documented in “GROUND MOTION ATTENUATION RELATIONS FOR THE CENTRAL AND EASTERN UNITED STATES” (Final report, June 30, 2001: Report to U.S. Geological Survey for award 99HQGR0098). This GMPE is used by the National Seismic Hazard Mapping Project (NSHMP) for the 2008 US hazard model.
Document available at: http://earthquake.usgs.gov/hazards/products/conterminous/2002/99HQGR0098.pdf
This class replicates the algorithm for the Somerville et. al. 2001 GMPE as coded in the subroutine getSomer in the hazgridXnga2.f Fortran code available at: http://earthquake.usgs.gov/hazards/products/conterminous/2008/software/
Coefficients are given for the B/C site conditions.
Coefficient table obtained from coefficient arrays (a1, a2, a3, a4, a5, a6, a7, sig0) defined in subroutine getSomer in hazgridXnga2.f
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 rjb
Required rupture parameter is only magnitude (Mw).
No site parameters required