Pablo Lara , Hernando Tavera, Quentin Bletery , Jean Paul Ampuero , Adolfo Inza, David Portugal, Benazir Orihuela, Fernando Meza

We present the implementation and testing of the seismological components of the Peruvian Earthquake Early Warning System (Sistema de Alerta Sísmica Peruano, SASPe). SASPe is designed to send alert messages to areas located within a given distance from the epicenter of large (magnitude ≥ 6.0) subduction earthquakes, with a first alert based on data available 3 seconds after the arrival of the P wave on the nearest station. The system comprises a dedicated network of 111 strong-motion stations installed along the Peruvian coast. During over 2 years of testing, the magnitude estimates are virtually unbiased, with no false positives or false negatives. In the most critical virtual scenarios of earthquakes occurring within 57 km from populated areas, SASPe can provide user lead times of up to 8 seconds. For more distant areas (from 70 km to 120 km), lead times range from 10 to 20 seconds. Once the construction of the alert broadcasting system by the civil defense authority is finalized, SASPe will provide warning to 18 million residents of the coast of Peru. We validate the algorithm of the system on recent major earthquakes in other regions, demonstrating its effectiveness and versatility for global deployment.