Analysis of Tsunami Tide Gauge Records Following the 2016 Ecuadorian Earthquake and Tsunami

Abstract

The devastating April 16, 2016, Pedernales, Ecuador, Mw 7.8 earthquake was among a sequence of ruptures that occurred along the seismically segmented North Andean subduction zone. It caused 700 fatalities, and more than 7,000 people were injured. The magnitude and location of it were similar to those of the May 14, 1942, earthquake, relaxing some of the strain accumulation that had built up over more than 74 years. A weak tsunami was detected in four nearby tide gauges. Analysis of the records provides useful information on the earthquake and tsunami. An estimate of 6.5 cm of coseismic subsidence was reported at the Bahía de Caráquez and Manta locations, while no movement was detected at Esmeraldas and La Libertad. The analysis also supports the existence of two major seismic asperities and a weaker one farther south. A tsunami resonance occurred at the Bay of Salinas, the location of La Libertad, even though the bay is very wide. It was fortunate that it was inconsequential, this time, because the incoming wave was substantially dissipated.