GROUND MOTION PREDICTION EQUATION (GMPE) FOR EAST NUSA TENGGARA CALIBRATING THE WORLD MODEL WITH LOCAL SEISMIC DATA

Abstract

This study aims to develop a Ground Motion Prediction Equation (GMPE) tai-lored to the shallow crustal seismic characteristics of East Nusa Tenggara, Indo-nesia. The purpose is to support seismic hazard mapping and disaster mitigation planning using regionally relevant data. A total of 732 earthquake events were analyzed, with magnitudes ranging from 3.0 to 5.7 and depths between 10 km and 25.9 km, recorded from 2017 to 2023. Four models were evaluated: a linear regression model, the original Akkar and Bommer (2010) model, a calibrated version of the same model, and a newly developed model built using a hybrid optimization method combining Differential Evolution and Least Squares. Model performance was assessed using root mean square error (RMSE), standard devia-tion, attenuation curves, and residual analysis. Results show that the newly de-veloped model performed best, with the lowest RMSE of 0.9252 and the most stable residual distribution. This model effectively captures ground motion char-acteristics and provides a reliable basis for accurate seismic hazard assessment in the region, supporting safer and more sustainable spatial planning.