Meteotsunamis Occurring Along The Southwest Coast Of South America During An Intense Storm

In this paper, we report meteotsunamis occurring along the Chilean and Peruvian coasts. These atmospherically induced tsunami-like oscillations were instrumentally recorded during an intense storm that affected central Chile on August 8th, 2015. The storm was characterized by strong winds, a locally unprecedented atmospheric low pressure and intense sea-level oscillations which caused six casualties and severe damage to infrastructure along ~500 km of coastline. The meteotsunamis are analyzed on both regional and local scales. On the regional scale, the temporal behavior and spatial behavior were discussed from the analysis of various tide gauges covering roughly 3000 km of the southwest coast of South America, between Callao, in central Peru, and Lebu, in southern Chile. Surprisingly, the phenomenon was recorded in the majority of the tide gauges in this vast region. On the area constrained by the storm region, a more detailed analysis is performed. We confirm the atmospheric origin of these intense sea-level oscillations by further analyzing meteorological records of air pressure and wind. An attempt to explain local (shelf and harbor) resonant mechanisms is achieved by means of wavelet analysis, while Greenspan and Proudman resonance mechanisms are superficially analyzed. Our results indicate that large meteotsunamis can occur along the west coast of South America and, when combined with other meteooceanographic conditions, may cause damage levels comparable to those resulting from Mw >8 earthquake generated tsunamis.