Advances in the Chilean Tsunami Warning System and Application of the TIME Project to the Chilean Coast

Abstract

The Chilean coast is frequently exposed to the effects of near and far field tsunamis generated in the Pacific Ocean. For instance, the catastrophic events of 1868 and 1877 overwhelmed the coast of the northern region of the country. During this century, the most significant disaster was the 1960 Valdivia earthquake and tsunami. It is well known that this event had a great impact on the coasts of most of the coastal states in the Pacific Ocean, mostly in Hawaii and Japan. The most recent event recorded in the Chilean coast was the "good tsunami" which occurred in Antofagasta, 1995. This historic situation has contributed to an awareness of the tsunami threat and therefore to the development of research on several aspects of this phenomenon in Chile. In the last few years, new developments in technology have made it possible to improve the quality of the information to assess the potential risk of a tsunami event off the Chilean coast. Since 1996, the TREMORS system has been operating in Chile. This is a seismic monitoring system that improves the existing seismic network and tsunami warning system in Chile, giving information in real time of seismic parameters and their relationship with some of the parameters of tsunami generation to estimate the risk. As a very important complement to the operative work, inundation maps by tsunamis for the Chilean coast have been developed, following the techniques of the TIME (Tsunami Inundation Modeling Exchange) project. The first maps for the four largest port cities in the northern part of Chile, namely Arica, Iquique, Antofagasta and Mejillones have been completed during 1997 and 1998. It is well known that the two northern most cities, Arica and Iquique ports, are located in a "seismic gap" zone. These inundation maps are being used for tsunami hazard planning by the national civil protection agency (ONEMI) and other governmental institutions.