Advances in the Chilean tsunami warning system and application for the TIME project on the Chilean Coast.

Dante Gutierrez
SHOA Tsunami Warning System, Chile.
E-mail: tsunamis@shoa.cl

The Chilean coast is currently exposed to the effects of near and far field tsunamis generated in the Pacific Ocean. For instance, the catastrophic events of the last century, 1868 and 1877, overwhelmed the coast of the northern region of the country. During this century, the most important disaster was the 1960 earthquake and tsunami in Valdivia, in the south of the country. It is well known that this event had a great impact on the coasts of most of the neighbouring countries in the Pacific Ocean, mostly in Hawaii Island and Japan. The last important event recorded along the Chilean coast was the "good tsunami" which occurred in Antofagasta, 1995.

This historic situation has contributed to an awareness of the risk involved and therefore to the development of research on the subject in Chile. The organisation in charge of detecting and issuing the warning is the Hydrographic and Oceanographic Service of the Chilean Navy (SHOA). The tsunami warning head office is located in the Department of Oceanography of SHOA. 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 1995, a TREMORS System has been operating in Chile. This is a seismic monitoring equipment 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. An very good instance of the application and utility of the technology was the tsunami warning issued by SHOA for the 1996 Chimbote earthquake in Peru.

As a very important complement to the operative work, SHOA has been working actively in the processing of inundation maps by tsunamis for the Chilean coast, using the TIME project technology. The first maps finished during 1997 and 1998 are the ones of the four largest cities in the northern part of Chile; namely Arica, Iquique, Antofagasta and Mejillones. Inundation maps have being used for tsunami hazard planning by the national civil protection agency (ONEMI) and other government institutions.