Task B: Reference Rock


  • To select the reference rock conditions to be used for simulations and GMPE development.
  • To develop amplification factors or models to be used to remove site effects at recording stations.

The Geotechnical WG is responsible for selecting the center, body and range of the shear-wave velocity and kappa of the reference rock to be used for the GMPEs and simulations. This task involves the analysis of recorded data for CENA, coming both from the A Task and from additional gathering of data. The Geotechnical WG will also develop a simple method for adjusting the recordings in the CENA database to the reference rock conditions. The site-corrected data are provided to the Path/Source WG for evaluation of the need for regionalizing the ground motion attenuation (Task C).

Note: The Geotechnical WG is also tasked to develop a site effects model for NGA-East, but this task is not formally part of the SSHAC Level 3 process.