Towards Public Earthquake Early Warning in Switzerland, Greece, Romania, and Croatia

EEW is in operation in many places around the globe, but no country in Europe currently offers a public alert system despite significant seismic risk. Recently, the Swiss Seismological Service (SED) at ETH Zurich, in collaboration with local agencies, has rolled out public EEW systems across Central America using their internally developed algorithms and mobile phone application. The ETH-SED SeisComP EEW (ESE) system consists of two algorithms - the point source Virtual Seismologist (VS) and the Finite fault rupture detector (Finder). The mobile phone application relies on Firecloud messaging and Apple Push Notifications and is available for Android and iOS users. It has proven reliable to send low-latency alerts to several hundred of thousand users.We are currently installing and testing the ESE system in Europe in countries where the earthquake hazard ranges from moderate (Switzerland-SED) to high (Greece-NOA, Romania-NIEP, Croatia-UniZG). Here, we present the developments undertaken over the last year in those countries and report on the algorithm performance and alert distribution for recent events. We discuss the remaining challenges and communication strategies towards public release.This work has benefited from funding within the TRANSFORM² project, European Commission project number 101188365 (HORIZON-INFRA-2024-DEV-01-01 call); and from the Seconds Matter project, SNSF-MAPS project numbers IZ11Z0230881 and F-RO-CH-2024-0263.