Package gov.usgs.earthquake.nshmp.gmm

Class Geomatrix_1993

java.lang.Object
gov.usgs.earthquake.nshmp.gmm.Geomatrix_1993
All Implemented Interfaces:
GroundMotionModel
public class Geomatrix_1993 extends Object implements GroundMotionModel
Implementation of the subduction interface ground motion model by Geomatrix consultants (1993) to support the 2007 Alaska NSHM. In the fortran codes used at the time, this GMM is noted as a 'Youngs and Coppersmith variation'. Although similar to Youngs et al. (1997), that GMM has quite a few add ons for site terms not supported or required by the 2007 Alaska NSHM such that it is simpler to have a standalone implementation.

Note: Direct instantiation of GroundMotionModels is prohibited. Use Gmm.instance(Imt) to retrieve an instance for a desired Imt.

Reference: Youngs, R.R., Chiou, S.-J., Silva, W.J., and Humphrey, J.R., 1997, Strong ground motion ground motion models for subduction zone earthquakes: Seismological Research Letters, v. 68, p. 58-73.

doi: 10.1785/gssrl.68.1.58

Component: Geometric mean of two horizontal components

Author:
U.S. Geological Survey
See Also:

  • Method Details

    • imt

      public Imt imt()
      Description copied from interface: GroundMotionModel
      The intensity measure type (IMT) of this GMM instance.
      Specified by:
      imt in interface GroundMotionModel

    • calc

      public final LogicTree<GroundMotion> calc(GmmInput in)
      Description copied from interface: GroundMotionModel
      Computes a logic tree of scalar ground motions and standard deviations for the supplied arguments. This method is implemented by GMMs to provide the horizontal peak ground acceleration and (optionally) velocity (PGA, PGV) as well as 5% damped pseudo-spectral acceleration for periods between 0.01 s and 10 s. For most modern GMMs, ground motions are computed as the average horizontal component (RotD50) but many older GMMs use some other average horizontal measure (e.g. GMRotI50).
      Specified by:
      calc in interface GroundMotionModel
      Parameters:
      in - a ground motion model input argument container