As a result of the earthquake of April 21, 2007, in the Aysén Fjord, Chile, a series of different types of landslides were generated, most of which affected the coastline surrounding the fjord. Among these landslides, a rock avalanche occurred in the Punta Cola sector, which resulted in a rock avalanche that reached the coast and produced a tsunami that affected populated sectors. The main objective of the following work is to perform a back analysis of geological and geotechnical features and compare computation volumes obtained with limit equilibrium analysis and the onshore volume avalanche. All this within an interconnected workflow between implicit modeling for the determination of domains and geometry; and 3D limit equilibrium analysis. The 3D slope stability captured the anisotropic influence on the sliding mass shape, and further comparison with digital elevation post event compared between the computed and observed landslide volumes. This study presents the importance of the proper use of field data on the context of 3D model analysis, the benefits of a combined geological-geotechnical analysis schema and the use of limit equilibrium method for rock failure mechanism driven by discontinuities sets.