Abstract

The 2015 Illapel earthquake sequence in Central Chile, occurred along the subduction zone interface in a known seismic gap. The main event triggered tsunami waves that damaged structures along the coast, while the surface ground motion induced localized liquefaction, settlement of bridge abutments, rockfall, debris flow, and collapse in several adobe structures. Damage to modern infrastructure was limited, although there was widespread tsunamiinduced damage to low rise residential homes adjacent to the shoreline. Shear wave measurements were performed at potentially liquefiable sites to test recent Vs-based liquefaction susceptibility approaches. This paper describes the earthquake and tsunami effects on retaining structures, bridge abutments, and cuts along Chile's main highway. Tsunami waves redistribute sand along the coast, obscuring evidence of liquefaction within minutes. This suggests that liquefaction occurrence may be under estimated in coastal zones. Importantly, the areas with the greatest coseismic slip, concentrated the largest volumes of rockfall, which suggests that coseismic slip maps, generated immediately after the shaking stops, can provide a first order indication about where to expect damage during future major events.