NUMERICAL SIMULATION OF NEW PROPOSED TSUNAMI SCENARIOS FOR IQUIQUE, CHILE

摘要

Iquique is located in northern Chile, and it has an important activity related to tourism and commerce. The last major earthquake and tsunami in northern Chile took place in 1877 with an estimated magnitude of 8.8. The generated tsunami reached an inundation height of 5-6 m. Since then, the accumulated energy was estimated to be enough to generate another Mw 8.8 earthquake. However, on April 2014, a Mw 8.1 earthquake took place, which released only about 20% of the total accumulated energy. Therefore, a similar or even larger earthquake could occur in the near future. The present paper analyzes the propagation and inundation of possible future tsunamis for the Iquique area in order that proper mitigation measures can be proposed. Tsunami numerical simulations were performed with 5 nested grids by means of the NEOWAVE model with a highest grid resolution of 10m. The results showed that tsunamis generated by the north and south segments would not generate a significant inundation area. A major tsunami could generate a flow depth up to 5m which is large enough to affect most of the important commercial areas of Iquique. Furthermore, it can be observed that the inundation can also occur on both sides of the Cavancha peninsula, thus transforming the peninsula into an island, thus evacuation routes are cut off. Moreover, the combination of tsunami source areas with different initiation time could generate even larger inundation.