Evolution of Ground-Motion Prediction Equations Developments Based on Graizer-Kalkan Modular Filter-Based Approach

Session: Forthcoming Updates of the USGS NSHMs: Hawaii, Conterminous U.S. and Alaska
Type: Oral
Date: 4/28/2020
Time: 02:45 PM
Room: 230 + 235
Description: 

A new modular filter-based approach to ground motion prediction equations (GMPE) development was first introduced by Graizer and Kalkan (2007, 2009). A unique feature of the model is its new functional form explicitly integrating peak ground acceleration (PGA) as a scaling factor. The predictive model of ground motion spectral shape (i.e., normalized response spectrum) is generated as a continuous function of few parameters: moment magnitude, closest distance to the fault and V_S30 (time-averaged shear-wave velocity in the upper 30 m) as independent variables. Originally the spectral shape function was developed for active crustal regions (ACR) (Graizer and Kalkan, 2009) and later it was modified to fit stable continental regions (SCR) (Graizer, 2016). In the original model we used fixed shapes for PGA and spectral shapes, while in latest models spectral amplitudes are adjusted based on magnitude, distance and VS30 residuals resulting in lower sigma. We used Pacific Earthquake Engineering Research (PEER) Center Next Generation Attenuation ground motion NGA-East and NGA-West2 databases to develop GMPEs for the “average” (RotD50) horizontal components of PGA, and 5% damped elastic pseudo-absolute acceleration response spectral ordinates (PSA) at periods ranging from 0.01 to 10 s.

The latest models assume bilinear attenuation slope reflecting distance attenuation of shear and surface waves. They also incorporate apparent anelastic (intrinsic and scattering) attenuation of response spectral acceleration which is different from the classical seismological quality factors and can be adjusted depending upon the region’s properties. The new ACR GMPE is applicable for earthquakes with 4.0≤M≤8.5, rupture distances of 0≤R_rup≤400 km, sites having V_S30 in the range from 150≤V_S30≤1500 m∕s, and for spectral periods of 0.01≤T≤10 s (Graizer, 2018). The SCR GMPEs cover the following range: 4.0≤M≤8.5, 0≤R_rup≤1000 km, 200≤V_S30≤2800 m/s and periods of 0.01≤T≤10 s (Graizer, 2016 and 2017).

Presenting Author: Vladimir Graizer

Authors