On February 27, 2010, a megathrust earthquake
of Mw 8.8 (USGS) provoked a destructive tsunami in Chile. The tsunami damaged about
600 km area along the coast of Chile, including the coastal towns of Dichato
and Tumbes in the Bio-Bio region and Robinson Crusoe Island on the archipelago
of Juan Fernandez, about 670 km off the coast of Chile. To estimate the
structural damage in a quantitative manner for the areas mentioned, tsunami
fragility functions were developed. Using Tohoku University's Numerical
Analysis Model for Investigation of Near-field tsunamis (TUNAMI) for the
numerical simulation to obtain the propagation and inundation depths and visual
inspection of satellite images for the damage data, the fragility curves for
Juan Fernandez, Tumbes, and Dichato were constructed. The obtained curves
suggest that for an inundation depth of one meter, the damage probability is
7%, 48%, and 82% for Tumbes, Dichato, and Juan Fernandez, respectively. The
similarity of the construction type (wood, masonry, and mixed) indicates that
the areas' exposure and building configuration has the most significant impact
on the structural damage, considering that Juan Fernandez island was not
affected by the ground motion of the 2010 event.
Keywords: Tsunami, Fragility function, 2010 Maule Earthquake, Chile