Elisa Zuccolo

In this study, a region-specific empirical fragility model is developed for the historical masonry building stock of Friuli Venezia Giulia (Northeastern Italy) using the damage database of the 1976 Mw6.4 Friuli earthquake and intensity measures derived from broadband three-dimensional physics-based simulations. The historical damage survey is first processed through data cleaning, geolocation, and completion to obtain a dataset suitable for fragility calibration. Ground-motion intensity measures are then estimated using a broadband simulation framework based on the spectral-element code SPEED coupled with the ANN2BB procedure, enabling the computation of intensity measures such as Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV), Peak Ground Displacement (PGD), Arias intensity, Housner intensity, and average spectral acceleration. The simulated ground-motion field is evaluated through comparisons with instrumental recordings, macroseismic observations, and an advanced empirical shaking scenario developed by the Italian National Institute of Geophysics and Volcanology (INGV) for the same event. Fragility functions are subsequently calibrated using maximum likelihood estimation for four representative masonry building typologies. The original EMS-98 damage states are further regrouped to address the limited resolution of the historical survey while improving their suitability for regional rapid damage assessment. The resulting fragility functions reproduce relevant features of the observed damage distribution and are broadly consistent with those obtained using the INGV empirical shaking scenario, particularly for PGV. The proposed framework demonstrates the potential of combining historical damage observations with broadband physics-based simulations to derive region-specific fragility functions and provides a basis for improving rapid damage scenario assessment in Friuli Venezia Giulia.

The TeRABIT project allowed to strategically federate three leading Research Infrastructures in Italy (HPC-BD-AI of INFN, GARR-T and PRACE-Italy of OGS) to provide to researchers a hyperconnected computing and data environment where to operate and develop new innovative services. The availability of a distributed ultra-high speed network, classical and cloud-based HPC resources allowed to create the novel UrgentShake workflow service. The service is based on a novel system designed to enable physics-based ground motion simulations triggered in real-time by OGS alerts. This service targets the critical requirement for urgent ground shaking assessment of seismic events, demonstrating how TeRABIT can support time-sensitive, socially relevant applications through seamless access to federated HPC and data services. UrgentShake demonstrates the use of a federated infrastructure in which multiple computational backends are available, including edge computing nodes, thereby enhancing computational redundancy and mitigating the risk of service disruption due to failures in centralized HPC systems. The Use Case required an extensive dialogue between researchers and the operators of the infrastructures, as well as the development of new skills by the researchers to efficiently create the workflow. Within both the global and European landscape, UrgentShake represents a further step toward the operationalization of urgent computing in Europe and contributes to advancing the exploitation of HPC research infrastructures in several ways. Importantly, the system goes beyond a purely demonstrative use case, having reached Technology Readiness Level (TRL) 7-8, thereby representing a near-operational solution validated in a real-world environment.

Emergency Condition Assessments (ECAs) are rapid evaluations conducted during or immediately after hazard events to support emergency decision making. Beyond response, ECAs are increasingly used for preparedness and emergency planning, enabling the testing of alternative hazard scenarios. However, the operational use of multi-hazard risk assessments for ECAs remains limited, particularly in cross-border settings, due to challenges with spatial resolution, data harmonisation, and the integration of critical infrastructure and their interdependencies.The DG ECHO–funded BORIS2 project addresses these challenges by delivering a transferable methodology and operational tool to support strategic emergency planning decisions. Building on the BORIS project (2021–2022), which established a minimum standard for cross-border seismic and flood risk assessment at the municipal scale, BORIS2 adapts the methodology for application at the sub-municipal level (grid-based units). This refinement enables the identification of urban areas most affected by single and compound hazard scenarios, improving preparedness for the emergency phase. BORIS2 expands the concept of the Limit Condition for the Emergency (LCE), originally developed by the Italian Civil Protection Department, by embedding it within a multi-hazard and cross-border framework applicable across different national contexts. A scenario-driven approach is used to assess the impacts of seismic, flood, and combined hazard events on buildings, assets, and critical infrastructure, explicitly accounting for infrastructure networks and functional dependencies relevant for emergency response. The methodology was applied and evaluated through three pilot applications in cross-border regions between Italy and Slovenia, Slovenia and Austria, and in an urban pilot area in Montenegro, demonstrating its applicability both within and outside the EU. All data sets, calculations and results are managed via the BORIS2 platform, which provides different options for visualising results using maps and tables, and where hotspots of interest can also be defined. This contribution focuses on the practical implementation of the BORIS2 framework and presents selected examples of single- and multi-hazard emergency condition assessments. Although the results primarily serve as proof of concept due to data limitations, the pilots highlight both opportunities and persistent challenges in operationalising multi-hazard risk assessments for emergency planning.

In this work we evaluate the use of Markov-modulated Poisson Process (MMPP) in the framework of the computation of Peak Ground Acceleration (PGA) for a 475-year return period through a classical Time-Dependent Probabilistic Seismic Hazard Assessment (TD-PSHA) approach. The catalogue of Southern Spain spanning from 1970 to 2023 has been selected using several tectonic zones from the nation seismic zonation as masks for the extraction, then homogenized and declustered.The MMPP model has been used for the computation of the seismic activity rate and has been tested with different completeness magnitudes (Mc) and number of states. Clear state transitions and coherent results (the high seismic activity rate state corresponds to periods with more high-magnitude earthquakes) can be identified for the Mw3.2 Mc with two states. A set of Ground Motion Models (GMMs) has been preselected and, using accelerometric data from the region, these GMMs have been ranked and used within a logic tree. The hazard curves (at the sites of Lorca, Murcia, Granada and Vera) and the hazard maps have been computed for each MMPP state and have been compared with other studies. The results show that higher PGA values have been obtained in the provinces of Granada, Málaga, Córdoba and Sevilla compared to previous studies. The hazard curves show high Probabilities of Exceedance (PoE) for lower PGA values in the selected sites and lower PoE for the high-end (PGA > 0.3g) of the considered PGA range when compared with other models.We finally explored whether the proposed scheme can also use tectonic zonation information, splitting the investigated region in sub-zones (given that enough events are selected for each zone), following the approach described in Montiel-Lopez et al. (NHESS, 2025).

Accounting for the finite spatial extent of earthquake rupture is critical for effective regional Earthquake Early Warning (EEW), particularly for large events where point-source assumptions may fail. The Finite fault rupture Detector (FinDer) algorithm addresses this challenge by rapidly inferring the location, extent, and orientation of an ongoing earthquake fault rupture through comparison of the observed spatial distributions of high-frequency ground-motion amplitudes with pre-calculated templates derived from empirical ground motion models. Northeastern Italy, characterized by moderate-to-large seismicity primarily associated with active reverse and strike-slip faulting, represents a suitable test region for finite-fault-based EEW. We evaluate FinDer performance using a combination of real-time detections (MW < 4.5) and offline playback experiments (5.5 < MW < 6.7), acknowledging that real-time EEW timeliness is affected by telemetry latency in the current seismic station network. Results show rapid convergence toward stable event locations and magnitudes, while line-source orientation remains weakly constrained, especially for small magnitude events. Sensitivity analyses indicate that increasing station density improves the stability of source-parameter estimates, and that amplification factor-based adjustments for site effects reduce systematic biases in FinDer’s template-matching solutions. Lead times estimated from offline playback tests are also evaluated relative to macroseismic intensity thresholds corresponding to slight damage in unreinforced masonry buildings, with selected scenarios yielding non-negligible lead times. Overall, the results suggest that a properly configured FinDer-based EEW system, supported by real-time telemetry, could provide significant benefits for seismic-risk mitigation in Northeastern Italy. Nevertheless, template simplifications and the neglect of radiation-pattern effects remain major limitations, particularly for reliable strike estimation in smaller events (MW < 4.5).

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.

The rapid response system currently in operation in northeastern Italy is based on the U.S. Geological Survey ShakeMap tool, which integrates ground-motion observations with selected ground-motion models (GMMs), similar to the systems used worldwide. To overcome the well-known limitations of conventional GMMs, a complementary system called UrgentShake, which uses physics-based ground-motion simulations, is currently being developed. The system integrates a kinematic description of an extended seismic source and captures the complex propagation of seismic waves through the heterogeneous subsurface of the region, considering its geological characteristics and topography. The development of UrgentShake is enabled by the use of high-performance computing facilities, which allow expediting the process, ensuring timely generation of seismic scenarios. The capability of generating near-real-time earthquake scenarios under strict time constraints following a seismic event is currently under investigation. In this initial phase, the system has been established as a prototype to showcase its potential, with planned refinements aimed at enhancing both the accuracy of ground-shaking predictions and its practical applicability in real-world scenarios. These advancements will enable regional civil protection authorities to make informed, timely decisions for managing seismic emergencies and coordinating response efforts effectively.

Earthquakes pose a significant threat worldwide, requiring rapid and accurate damage assessments to guide emergency response efforts. While empirical ground motion models are commonly used for their speed and simplicity, they often fail to account for critical factors such as site effects and the spatial variability of ground shaking. Physics-based ground shaking simulations can provide a more accurate alternative by modelling fault rupture, wave propagation and local site effects. However, their application in the near real-time has been limited due to computational complexity and long processing times. To overcome these limitations, we have developed UrgentShake, an HPC-based system designed to generate physics-based ground shaking scenarios under strict time constraints. A key focus of UrgentShake is the implementation of efficient strategies to reduce the computational time required to produce reliable solutions without compromising accuracy. Preliminary evaluations on two reference seismic events demonstrate UrgentShake's capability to significantly reduce time-to-solution, ensuring its potential to meet the critical timing demands of seismic emergency responses.

CRISIS project aims at improving the disaster and emergency management through building a harmonized and efficient system for risk assessment of basic services and transport infrastructure in the targeted cross-border region. The main project activities include: (1) Cross-border multi hazard assessment; (2) Needs assessment; (3) Cross- border multi-risk assessment; and (4) Development of cross-border web base platform for risk assessment and management. The main stakeholder of the project is the civil protection and disaster management national authorities in the cross-border region where more than 500.000 inhabitants live, as well as all academic partner institutions that will share the knowledge and strengthen the mutual cooperation.