# Source code for openquake.hazardlib.gsim.geomatrix_1993

```
# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright (C) 2014-2017 GEM Foundation
#
# OpenQuake is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# OpenQuake is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with OpenQuake. If not, see <http://www.gnu.org/licenses/>.
"""
Module exports :class:`Geomatrix1993SSlabNSHMP2008`.
"""
from __future__ import division
import numpy as np
from openquake.hazardlib.gsim.base import CoeffsTable, GMPE
from openquake.hazardlib import const
from openquake.hazardlib.imt import PGA, SA
[docs]class Geomatrix1993SSlabNSHMP2008(GMPE):
"""
Implements GMPE for subduction intraslab events developed by Geomatrix
Consultants, Inc., 1993, "Seismic margin earthquake for the Trojan site:
Final unpublished report prepared for Portland General Electric Trojan
Nuclear Plant", Ranier, Oregon.
This class implements the equation as coded in the subroutine ``getGeom``
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.
"""
#: Supported tectonic region type is subduction intraslab
DEFINED_FOR_TECTONIC_REGION_TYPE = const.TRT.SUBDUCTION_INTRASLAB
#: Supported intensity measure types are spectral acceleration,
#: and peak ground acceleration
DEFINED_FOR_INTENSITY_MEASURE_TYPES = set([
PGA,
SA
])
#: Supported intensity measure component is the geometric mean of
#: two horizontal components
DEFINED_FOR_INTENSITY_MEASURE_COMPONENT = const.IMC.AVERAGE_HORIZONTAL
#: Supported standard deviation type is only total.
DEFINED_FOR_STANDARD_DEVIATION_TYPES = set([
const.StdDev.TOTAL
])
#: No site parameters required
REQUIRES_SITES_PARAMETERS = set()
#: Required rupture parameters are magnitude and top of rupture depth
REQUIRES_RUPTURE_PARAMETERS = set(('mag', 'ztor'))
#: Required distance measure is rrup (closest distance to rupture)
REQUIRES_DISTANCES = set(('rrup', ))
[docs] def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
"""
See :meth:`superclass method
<.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
for spec of input and result values.
"""
assert all(stddev_type in self.DEFINED_FOR_STANDARD_DEVIATION_TYPES
for stddev_type in stddev_types)
C = self.COEFFS[imt]
mean = self._compute_mean(C, rup.mag, rup.ztor, dists.rrup)
stddevs = self._compute_stddevs(
C, rup.mag, dists.rrup.shape, stddev_types
)
return mean, stddevs
def _compute_mean(self, C, mag, ztor, rrup):
"""
Compute mean value as in ``subroutine getGeom`` in ``hazgridXnga2.f``
"""
gc0 = 0.2418
ci = 0.3846
gch = 0.00607
g4 = 1.7818
ge = 0.554
gm = 1.414
mean = (
gc0 + ci + ztor * gch + C['gc1'] +
gm * mag + C['gc2'] * (10 - mag) ** 3 +
C['gc3'] * np.log(rrup + g4 * np.exp(ge * mag))
)
return mean
def _compute_stddevs(self, C, mag, num_sites, stddev_types):
"""
Return total standard deviation.
"""
std_total = C['gc4'] + C['gc5'] * np.minimum(8., mag)
stddevs = []
for _ in stddev_types:
stddevs.append(np.zeros(num_sites) + std_total)
return stddevs
#: Coefficient table obtained from coefficient arrays and variables
#: defined in subroutine getGeom in hazgridXnga2.f
COEFFS = CoeffsTable(sa_damping=5, table="""\
IMT gc1 gc2 gc3 gc4 gc5
pga 0.0 0.0 -2.556 1.45 -0.1
0.1 1.1880 -0.0011 -2.6550 1.45 -0.1
0.2 0.722 -0.0027 -2.528 1.45 -0.1
0.3 0.246 -0.0036 -2.454 1.45 -0.1
0.5 -0.4 -0.0048 -2.36 1.45 -0.1
1.0 -1.736 -0.0064 -2.234 1.45 -0.1
2.0 -3.3280 -0.0080 -2.107 1.55 -0.1
3.0 -4.511 -0.0089 -2.033 1.65 -0.1
""")
```