Feasibility study of an integrated earthquake and tsunami early warning system

Current Tsunami Early Warning Systems (TEWS) aim to issue an initial alert within minutes after a seismic event, relying on rapid estimates of earthquake source parameters derived from teleseismic and regional seismic data. For coastal areas located in the near-distance range of a tsunamigenic source, reducing this alert time is critical to increase evacuation lead-time and enhance risk mitigation actions. In this study, we evaluate the integration of earthquake magnitude and location estimations from QuakeUp, an impact-based earthquake early warning system (EEWS), into a tsunami early warning system (TEWS) workflow. We investigate the trade-off between earliness and accuracy of the seismic source parameters and their impact on Probabilistic Tsunami Forecasting (PTF). A hindcast of the 30 October 2020 Mw7.0 Aegean Sea earthquake, whose tsunami reached nearby coasts within ~ 10 min demonstrated that QuakeUp can deliver stable and accurate hypocenter and magnitude estimates within ~ 40 s from origin time, comparable to those obtained by the Early-Est software within minutes, used operationally in the Mediterranean area. These rapid parameter estimates were used to run a PTF procedure, yielding runup predictions in reasonable agreement with observations. A second scenario, based on 150 simulated seismogram sets for Mw 6–7 earthquakes in the Messina Strait (Southern Italy) confirmed the ability of the integrated workflow to provide robust source estimates within one minute. This work represents the first demonstration of a combined EEWS-TEWS approach for near-field tsunamigenic earthquakes, highlighting its potential for dual risk mitigation.