Abstract Database

TSUNAMI HAZARD ASSESSMENT FOR THE CENTRAL COAST OF PERU USING NUMERICAL SIMULATIONS FOR THE 1974, 1966 AND 1746 EARTHQUAKES

MEE10521
Sheila Yauri
Supervisor: Yushiro FUJII, Bunichiro SHIBAZAKI
Country: Peru
Abstractfulltext

A comprehensive study of tsunami simulation for the two recent events in 1974 (Mw8.0), 1966 (Mw8.1) and one historical event in 1746 (Mw8.5-9.2) was carried out in order to constrain the tsunami source and evaluate the tsunami hazard in the central coast of Peru. We propose a seismic source for each event in 1974 and 1966 and evaluate the tsunami heights and arrival time by performing a tsunami simulation using a TUNAMI-N2 code that solves non-linear long wave equation. Also, in order to reproduce the historical tsunami in 1746, we carried out a simulation for scenarios with Mw of 8.5, 8.8, 9.0 and 9.2. Through a comparison among the historical tsunami descriptions, the scenarios with Mw 8.8-9.0 were found to be more representatives, which is consistent with the maximum tsunami heights observed from Huarmey to Barranco stations. Moreover, we adopt a more realistic future tsunami scenario using a predicted slip model from an interseismic coupling using GPS data provided by Pulido et al. (2011). This scenario shows an important coupling area facing Huacho Lima and Pisco cities and according to the moment deficit a repetitive event of the 1746 earthquake could occur. Also this model shows that the events in 1940, 1966, 1974 and 2007 have not released the total energy accumulated since 1746. From this scenario, the maximum tsunami height could be 7.8 m in Huacho station with a minimum arrival time of 25 min after the earthquake. In all the cases, we found that the tsunami travels faster to the south and slower to the north of Peru. The tsunami simulation using the bathymetry data of 30 arc-second resolution showed longer travel time and higher amplitude compared with the 1 arc-minute resolution, giving the former better results in the comparison between the synthetic and observed tide gauge records for the 1974 and 1966 events.