A risk-driven approach in assessing the potential effectiveness of earthquake early warning for schools in the Patras region, Greece

Earthquake early warning (EEW) constitute a major tool for seismic resilience enhancement in modern societies, helping mitigate some of the devastating effects of earthquakes (e.g., deaths, business interruption) in the face of increasing exposure and vulnerability to seismic events worldwide. However, traditional EEW approaches (such as feasibility studies and decision-making related to triggering alerts by different end users) are essentially based on seismological considerations. In this study, jointly developed with the University College London in the framework of the EU H2020 TURNkey Project (https://earthquake-turnkey.eu/), we adopt a risk-based approach to EEW. We present the results of a state-of-the-art feasibility study for EEW in schools performed across the Patras region of Greece, which combines traditional seismologically-driven EEW decision criteria (warning time) with proxy risk-oriented measures for earthquake impact (building fragility and the number of exposed students). The results, showing the effectiveness of EEW under certain conditions, are the premises for the demonstration of an innovative end-user-centred approach for improved risk-informed decision-making on triggering EEW alerts, which merges earthquake-engineering-related seismic performance assessment procedures and metrics with multi-criteria decision-making within an end-to-end probabilistic framework. The approach, demonstrated using an archetype school building for the case-study region, emphasizes that the best action (i.e., “trigger” or “don’t trigger” an EEW alert) for a given level of ground shaking depends on the stakeholder preferences towards the predicted damage/loss estimates consequences.