Physics-Based Ground Motion Simulations for the UNESCO World Heritage Site of Bagan, Myanmar

Bagan, a UNESCO World Heritage Site in central Myanmar, is highly vulnerable to seismic activities, necessitating a detailed assessment of potential earthquake ground motions. The present study identifies the fault conditions most critical to the Bagan monuments through a multi-scenario high-frequency simulation analysis, varying both the kinematic rupture characteristics and source locations for major faults within 300 km of the Bagan archaeological region. 3D physics-based broadband ground motions are generated using a multidimensional kinematic source model for the earthquake scenario with highest spectral acceleration corresponding to the natural periods of the monuments. To achieve this, the 3D computational model developed by Basu and Raghukanth is utilized, incorporating spatial variations in material properties, regional attenuation, and topography. Subsequently, the model is evaluated at a monument site with recorded data for the 2016 Chauk earthquake, and the ground motions are simulated and assessed for 286 monument locations. Broadband ground motions generated using the physics-based multidimensional kinematic source model are compared with those obtained from the conventional hybrid approach of Basu and Raghukanth (2024), which combines physics-based low-frequency and stochastic high-frequency simulations. Thus, the study provides a crucial dataset for seismic risk assessment and conservation planning for Bagan’s invaluable cultural heritage.