A Comparative Analysis of Coastal and Open-Ocean Records of the Great Chilean Tsunamis of 2010, 2014 and 2015 off the Coast of Mexico

The three great earthquakes off the coast of Chile on 27 February 2010 (Maule, M_w 8.8), 1 April 2014 (Iquique, M_w 8.2) and 16 September 2015 (Illapel, M_w 8.3) generated major transoceanic tsunamis that spread throughout the Pacific Ocean and were measured by numerous coastal tide gauges and open-ocean DART stations. Statistical and spectral analyses of the tsunami waves from the events recorded on the Pacific coast of Mexico enabled us to estimate parameters of the waves along the coast and to compare statistical features of the events. We also identified three coastal “hot spots” (sites having maximum tsunami risk): Puerto Angel, Puerto Madero and Manzanillo. Based on the joint spectral analyses of the tsunamis and background noise, we have developed a method for using coastal observations to determine the underlying spectrum of tsunami waves in the deep ocean. The “reconstructed” open-ocean tsunami spectra are in close agreement with the actual tsunami spectra evaluated from direct analysis of the DART records offshore of Mexico. We have further used the spectral estimates to parameterize the energy of the three Chilean tsunamis based on the total open-ocean tsunami energy and frequency content of the individual events.