The September 16, 2015 Mw 8.3 Illapel, Chile Earthquake： characteristics of tsunami wave from near-field to far-field

作     者：REN Zhiyuan YUAN Ye WANG Peitao FAN Tingting WANG Juncheng HOU Jingming 

作者机构：National Marine Environmental Forecasting Center 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2017年第36卷第5期

页      面：73-82页

核心收录：

学科分类：07[理学] 0707[理学-海洋科学] 

基　　金：The Public Science and Technology Research Funds Projects of Ocean under contract No.201405026 the National Key Research and Development Program of China under contract No.2016YFC1401500 the Opening Fund of State Key Laboratory of Ocean Engineering under contract No.1604 

主　　题：2015 Illapel earthquake tsunami observation numerical modeling far-field near-field 

摘      要：On September 16, 2015, an earthquake with magnitude ofMw 8.3 occurred 46 km offshore from Illapel, Chile, generating a 4.4-m local tsunami measured at Coquimbo. In this study, the characteristics of tsunami are presented by a combination of analysis of observations and numerical simulation based on sources of USGS and NOAA. The records of 16 DART buoys in deep water, ten tidal gauges along coasts of near-field, and ten coastal gauges in the far-field are studied by applying Fourier analyses. The numerical simulation based on nonlinear shallow water equations and nested grids is carried out to provide overall tsunami propagation scenarios, and the results match well with the observations in deep water and but not well in coasts closed to the epicenter. Due to the short distance to the epicenter and the shelf resonance of southern Peru and Chile, the maximum amplitude ranged from 0.1 m to 2 m, except for Coquimbo. In deep water, the maximum amplitude of buoys decayed from 9.8 cm to 0.8 cm, suggesting a centimeter-scale Pacific-wide tsunami, while the governing period was 13-17 min and 32 min. Whereas in the far-field coastal region, the tsunami wave amplified to be around 0.2 m to 0.8 m, mostly as a result of run-up effect and resonance from coast reflection. Although the tsunami was relatively moderate in deep water, it still produced non-negligible tsunami hazards in local region and the coasts of farfield.