UrgentShake for Scenario-Based Ground Motion Simulations: Integrating Multiple Source Realizations with CyberShake

UrgentShake is an urgent computing system developed by OGS (National Institute of Oceanography and Applied Geophysics) for the rapid generation of physics-based ground shaking scenarios. It employs a distributed architecture across High-Performance Computing (HPC) and cloud infrastructures to perform numerical simulations in near real-time, providing reliable estimates of ground motion following significant seismic events in Northeastern Italy, thereby supporting decision-making by emergency management authorities.

Although primarily designed for rapid response to earthquakes, UrgentShake’s flexible architecture also makes it suitable for non-real-time applications, such as Civil Protection exercises and risk analyses. In these contexts, a single realization of a specific seismic source is not sufficient; instead, a suite of plausible scenarios is needed to define median, minimum and maximum estimates of ground shaking and potential impacts.

To address this need, a feasibility study was conducted to demonstrate the potential integration of UrgentShake with CyberShake, a physics-based platform for seismic hazard modeling that simulates many rupture scenarios. CyberShake simulations for a representative earthquake scenario were performed using the Graves and Pitarka stochastic rupture generator and the Anelastic Wave Propagation code on HPC resources at the Barcelona Supercomputing Centre. By generating multiple independent source realizations with varying nucleation points, fault geometries and rupture characteristics, this proof of concept illustrates how source-related uncertainties can be incorporated into UrgentShake to produce robust ground shaking scenarios. These scenarios can support Civil Protection training and preparedness activities while enabling physics-based damage assessments to inform risk analyses.