The seismic network of Chile

Abstract

Chile is frequently affected by large and potentially tsunamigenic and damaging earthquakes as a result of rapid convergence 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 earthquake, Chile began installing a modern real-time network of digital broadband/strong-motion and Global Positioning System (GPS) stations to better prepare for future and expected large damaging earthquakes. The network was designed to provide fast and accurate estimates of earthquake source parameters 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 systems 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 similar to 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 networks C and C1. Strong-motion data for recorded accelerations larger than 2%g are available through the CSN webpage.