A ground-motion model for the gulf coast region of the United States


In this study, the hybrid empirical method (HEM) was used to develop a new ground-motion model (GMM) for the Gulf Coast of the United States. We used five new empirical GMMs developed by the Pacific Earthquake Engineering Research Center for the Next Generation Attenuation-West2 project to estimate ground-motion intensity measures (GMIMs) in the host region. The new GMM is derived for the horizontal peak ground acceleration and response-spectral ordinates at periods ranging from 0.01 to 10 s, moment magnitudes ranging from M 3.5 to 8.0, and rupture distance (RRUP) as far as 1000 km from the site, although the GMMs are the best constrained for RRUP < 300–400 km. The predicted GMIMs are for a reference site defined as the Gulf Coast region hard rock with VS30 3000 m/ s and κ0 0:006 s, in which VS30 is the time-averaged shear-wave velocity in the top 30 m of the site profile, and κ0 is the total attenuation of the ground motion as it propagates through the site profile. Seismological parameters used to derive the GMIM stochastic estimates in the Gulf Coast target region are adopted from the most recent research and published information for the region. The seismological parameters for the western North America host region are adopted from Zandieh et al. (2017). The proposed GMM is compared with the Pezeshk et al. (2018) model, which is also a HEM approach, and was developed for central North America and excluded the Gulf Coast region to show the differences between the regions.

Publication Title

Bulletin of the Seismological Society of America