The Seismic Network of Chile

Chile is frequently affected by large and potentially tsunami- genic and damaging earthquakes as a result of rapid conver- gence of the Nazca plate beneath the South America plate. Ten M 8 or larger earthquakes have occurred along the Chilean coast in the past century, the largest of which was the 1960 M 9.5 Valdivia earthquake. After the 2010 M 8.8 Maule earth- quake, Chile began installing a modern real-time network of digital broadband/strong-motion and Global Positioning Sys- tem (GPS) stations to better prepare for future and expected large damaging earthquakes. The network was designed to pro- vide fast and accurate estimates of earthquake source parame- ters of potentially devastating earthquakes for emergency response applications, and was also capable of comprehensive characterization of Chilean seismicity necessary for long-term hazard assessment and mitigation activities. Beginning in 2013, the National Seismological Center (CSN) of the University of Chile was mandated by the Chilean government to implement a network of 65 permanent real-time broadband and strong- motion stations and 130 Global Navigation Satellite Systems (GNSS) monuments and receivers. These integrated sensor sys- tems were designed to provide accurate automatic earthquake locations and magnitudes necessary for tsunami warning and impact assessment. In near-real-time applications, the GPS stations become critical for determination of fault finiteness of M ∼ 7 or larger earthquakes. Operations of these systems also provide new insights into long-term deformation and associated spatiotemporal variations in seismicity, which are necessary in long-term earthquake hazards assessment and mitigation. In addition to the real-time system described above, 297 strong- motion offline instruments complement the network for engineering purposes. Broadband data in real time are publicly available through the Incorporated Research Institutions for Seismology Data Management Center (IRIS-DMC) under net- works C and C1. Strong-motion data for recorded accelerations larger than 2%g are available through the CSN webpage.