Ground motion prediction equations for distant subduction interface earthquakes based on empirical data in the Malay Peninsula and Japan

Ground motion prediction equations (GMPEs) for earthquakes that occur in subduction zones, including both interface and slab parts, have a major impact on seismic hazard analysis in many parts of the world. For example, in the Sumatran subduction region, there could be a remarkable hazard for the Malay Peninsula due to the large megathrust earthquakes that occur far from the region along the subduction interface. This study has developed new empirical spectral GMPEs for long-distance subduction interface earthquakes based on the recorded ground motion data in the Malay Peninsula and Japan. The compiled ground motion database is from hundreds of ground motion recordings due to twenty five reliably identified subduction interface events with moment magnitude [M] of 5.0-9.1 and hypocentral distance (Rhyp) up to 1300 km. The data from the large megathrust earthquakes with M ≥ 7.0 such as 2011 M 9.1 Tohoku-Japan, the 2007 M 8.5 earthquake near Bengkulu in Sumatra Island, 2005 M 8.6 Nias-Sumatra, and 2004 M 9.0 Aceh-Sumatra earthquakes were included in the database. The proposed GMPEs are able to predict peak ground acceleration (PGA), peak ground velocity (PGV), and 5% damped pseudo-spectral acceleration (PSA) for four different site classes based on the National Earthquake Hazards Reduction Program (NEHRP) site classification. The results of this study could be applied to develop logic tree frameworks for seismic hazard analyses of Peninsular Malaysia as well as the regions affected by large and distant subduction interface earthquake events.