shakelib.gmice.wgrw12

class shakelib.gmice.wgrw12.WGRW12

Bases: object

Implements the ground motion intensity conversion equations (GMICE) of Worden et al. (2012).

References

Worden, C. B., Gerstenberger, M. C., Rhoades, D. A., & Wald, D. J. (2012). Probabilistic relationships between ground‐motion parameters and modified Mercalli intensity in California. Bulletin of the Seismological Society of America, 102(1), 204-221.

DEFINED_FOR_INTENSITY_MEASURE_TYPES = {<class 'openquake.hazardlib.imt.PGA'>, <class 'openquake.hazardlib.imt.PGV'>, <class 'openquake.hazardlib.imt.SA'>}

DEFINED_FOR_SA_PERIODS = {0.3, 1.0, 3.0}

getMIfromGM(amps, imt, dists=None, mag=None)

Function to compute macroseismic intensity from ground-motion intensity. Supported ground-motion IMTs are PGA, PGV and PSA at 0.3, 1.0, and 3.0 sec periods.

Parameters:

• amps (ndarray) – Ground motion amplitude; natural log units; g for PGA and PSA, cm/s for PGV.
• imt (OpenQuake IMT) – Type the input amps (must be one of PGA, PGV, or SA). Supported SA periods are 0.3, 1.0, and 3.0 sec. [link] <http://docs.openquake.org/oq-hazardlib/master/imt.html>
• dists (ndarray) – Numpy array of distances from rupture (km).
• mag (float) – Earthquake magnitude.

Returns:

ndarray of Modified Mercalli Intensity and ndarray of dMMI / dln(amp) (i.e., the slope of the relationship at the point in question).

getGMfromMI(mmi, imt, dists=None, mag=None)

Function to tcompute ground-motion intensity from macroseismic intensity. Supported IMTs are PGA, PGV and PSA for 0.3, 1.0, and 3.0 sec periods.

Parameters:

• mmi (ndarray) – Macroseismic intensity.
• imt (OpenQuake IMT) – IMT of the requested ground-motions intensities (must be one of PGA, PGV, or SA). [link] <http://docs.openquake.org/oq-hazardlib/master/imt.html>
• dists (ndarray) – Rupture distances (km) to the corresponding MMIs.
• mag (float) – Earthquake magnitude.

Returns:

Ndarray of ground motion intensity in natural log of g for PGA and PSA, and natural log cm/s for PGV; ndarray of dln(amp) / dMMI (i.e., the slope of the relationship at the point in question).

getGM2MIsd()

Return a dictionary of standard deviations for the ground-motion to MMI conversion. The keys are the ground motion types.

Returns:Dictionary of GM to MI sigmas (in MMI units).

getMI2GMsd()

Return a dictionary of standard deviations for the MMI to ground-motion conversion. The keys are the ground motion types.

Returns:Dictionary of MI to GM sigmas (ln(PGM) units).

static getName()

Get the name of this GMICE.

Returns:String containing name of this GMICE.

static getScale()

Get the name of the PostScript file containing this GMICE’s scale.

Returns:Name of GMICE scale file.

static getMinMax()

Get the minimum and maximum MMI values produced by this GMICE.

Returns:Tuple of min and max values of GMICE.

static getDistanceType()