Somerville et al. 2001

class openquake.hazardlib.gsim.somerville_2001.SomervilleEtAl2001NSHMP2008

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.

COEFFS = <openquake.hazardlib.gsim.base.CoeffsTable object>

Coefficient table obtained from coefficient arrays (a1, a2, a3, a4, a5, a6, a7, sig0) defined in subroutine getSomer in hazgridXnga2.f

DEFINED_FOR_INTENSITY_MEASURE_COMPONENT = 'Average horizontal'

Supported intensity measure component is the geometric mean of attr:~openquake.hazardlib.const.IMC.AVERAGE_HORIZONTAL,

DEFINED_FOR_INTENSITY_MEASURE_TYPES = set([<class 'openquake.hazardlib.imt.SA'>, <class 'openquake.hazardlib.imt.PGA'>])

Supported intensity measure types are spectral acceleration, and peak ground acceleration

DEFINED_FOR_STANDARD_DEVIATION_TYPES = set(['Total'])

Supported standard deviation type is only total.

DEFINED_FOR_TECTONIC_REGION_TYPE = 'Stable Shallow Crust'

Supported tectonic region type is stable continental crust, given that the equations have been derived for central and eastern north America

REQUIRES_DISTANCES = set(['rjb'])

Required distance measure is rjb

REQUIRES_RUPTURE_PARAMETERS = set(['mag'])

Required rupture parameter is only magnitude (Mw).

REQUIRES_SITES_PARAMETERS = set([])

No site parameters required

get_mean_and_stddevs(sites, rup, dists, imt, stddev_types)

See superclass method for spec of input and result values.