Original paper

One hundred years of the rock fall triggered by the 1912 Acambay earthquake, Mexico

Ramírez-Herrera, María Teresa; Inbar, Moshe; Paulín, Gabriel Legorreta

Abstract

Rock falls triggered by earthquakes have been studied using various approaches (inventory, heuristic, statistic, and deterministic) and its implementation embedded into Geographic Information System-based applications that have provided a basis for understanding, evaluating, and mapping the hazard associated with earthquake-induced landslides. However, few studies of historical earthquake-induced rock falls and their geomorphologic characteristics have been published on Mexico. The first recorded scientific earthquake report in Mexico was written after the 1912 Acambay earthquake and eyewitness accounts were recorded soon after this event. In the area, rock fall deposits triggered by the 1912 (M 6.9) earthquake provide a unique opportunity to examine and characterize in detail the geomorphology of a historical rock fall. In this study, rock falls and block deposits triggered by the 1912 earthquake in the eastern portion of the Acambay graben are characterized with historic, field, geomorphic, and statistical data. Earthquake magnitude, slope morphology and lithology determined the origin, size and travel distance of blocks. The study shows that block size and travel distance from the escarpment do not correlate. These conclusions have important implications for modelling block falls, as well as for further hazard mapping in highly populated areas.

Keywords

rock fallearthquakelandslide hazardmexico