Implements GMPE developed by Idriss 2014 and published as “An NGA-West2 Empirical Model for Estimating the Horizontal Spectral Values Generated by Shallow Crustal Earthquakes. (2014, Earthquake Spectra, Volume 30, No. 3, pages 1155 - 1177).
Idriss (2014) defines the GMPE only for the case in which Vs30 >= 450 m/s. In the present implementation no check is made for the use of this model for sites with Vs30 < 450 m/s
Supported intensity measure component is orientation-independent measure RotD50
Supported intensity measure types are spectral acceleration, and peak ground acceleration
Supported standard deviation types are total
Supported tectonic region type is active shallow crust
Required distance measure is Rrup
Required rupture parameters are magnitude, and rake.
Required site parameters is Vs30