Coupled Tsunami-induced and liquefaction ground deformation during the Mw 7.7. Michoacan Earthquake

Abstract

Coastal zones are vital economic resources for many countries, with opportunities for tourism, fishing, transportation, and trade. However, the susceptibility of these areas to seismic hazards such as liquefaction and tsunamis exhibits a significant challenge to sustainable development and economic growth. Thus, identifying the geotechnical conditions that contribute to seismic vulnerability and the definition of high-risk areas are crucial steps for coastal infrastructure development planning. In Mexico, coastal areas along the Pacific Ocean are highly susceptible to seismic hazards, due to their proximity to active subduction zones, which have produced some of the most devastating earthquakes. Likewise, the presence of loose and saturated sediments, associated with the proximity of these coastal communities to the ocean, increases the risks of liquefaction and tsunami-induced ground deformation. In recent years, both phenomena have been observed after seismic events in several locations along this region. This paper examines the impact of the Mw 7.7 Michoacan earthquake that occurred on September 19, 2022, in Mexico, which triggered liquefaction in several coastal areas and activated a tsunami alert in four states on the Mexican Pacific Ocean coast. Key findings highlight crucial factors contributing to seismic hazards and provide insights for identifying vulnerable areas for future coastal infrastructure development. In addition, a five steps methodology for analyzing tsunami induced damage is described.