shakelib.gmice.wgrw12

class shakelib.gmice.wgrw12.WGRW12[source]

Bases: GMICE

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.

getMIfromGM(amps, imt, dists=None, mag=None)[source]

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)[source]

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()[source]

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()[source]

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).