Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

376 PATA Days 2024 theories and speculations. Recent archaeological findings and interdisciplinary research continue to shed light on the complex circumstances surrounding the decline of this once-thriving civilization (Clayton, 2020; Pérez- López et al., 2024). The history of Teotihuacan begins between the years 150 – 1 BCE, and it is related to volcanic eruptions: the eruption of the Popocatepetl, and the destruction of Cuicuilco city-state in the Xitle eruption (250 – 300 CE, Clayton, 2016; Manzanilla, 2015). Teotihuacan reached the maximum population between 100 – 200 CE, the Xolalpan, and Metepec phases (450 – 650 CE). Eventually, from 550 CE different authors (Manzanilla 2015; Clayton, 2020) reported a sharp decrease of inhabitants, fires, and collapsed buildings. This fact marked the beginning of the Epiclassic cultural Period in the central highlands of Mexico. In this work, we have applied the methodology of archaeoseismology and the Earthquake Archaeological Effects (EAE) proposed by Rodríguez- Pascua et al. (2011), (2023), for unravelling the destructions patterns observed in the Sun and Moon pyramids, and overall, several seismic effects and well- preserved ground-shacking patterns affecting the Feathered Serpent Temple (Pérez-López et al., 2010; 2012; 2019; 2024). Additionally, we have introduced and described a new EAE observed in the floating cantilever carved blocks that decorate the west side of the hidden staircase in the Feathered Serpent pyramid (Pérez-López et al., 2014). Fig. 2: Floating dipping broken corners affecting the Old Temple and the New Temple. a. Conceptual model. b. Detailed photograph of the dipping broken corner (white arrows) affecting the first row of the west staircase of the New Temple. c. Front view west staircase of the Old Temple. d. Lateral view of the north balusters (rafters) of the west staircase of OT showing imbricated blocks. e. Rotated and overturned blocks in the lower part of the west staircase of the Old Temple (white rectangle).