ALBERT

Description: The ATTAC project, or Alerta Temprana de Terremotos en América Central, aims to establish public earthquake early warning (EEW) systems in Central America. The region experiences frequent subduction and shallow crustal earthquakes and has a vulnerable building stock, along with a rapidly growing population density. EEW can reduce the fatalities and injuries that occur during strong earthquakes. The ATTAC project is building national EEW systems at seismic agencies in each of Guatemala (INSIVUMEH), El Salvador (MARN), Nicaragua (INETER), and Costa Rica (OVSICORI-UNA), with the collaboration of SED at ETH Zurich. The EEW systems are based on the ETHZ SeisComP EEW (ESE) add-on modules and include the Virtual Seismologist and FinDer algorithms. The project has deployed 70 low-latency accelerographs across the region and has implemented performance-tracking tools to monitor the network and EEW results in terms of accuracy and speed. The ESE dissemination module allows to select the best of the EEW solutions and to deliver targeted alerts via a mobile application and digital TV. Data analysis of the mobile application has shown promise (74% of users notified in 5 seconds). Although the number of active recipients is in the low thousands, it is scaling up. We demonstrate successful EEW for recent earthquakes with delay from event initiation to alert dissemination ranging from 10 to 15 seconds for shallow onshore seismicity and from 20 to 25 seconds for offshore or deep events. We focus on false alerts with software and configuration optimizations and establishing best practice in network management.