Mexico City, Mexico – A significant geological discovery in the west of Mexico City has been announced by researchers from the National Autonomous University of Mexico (UNAM), shedding light on the cause behind a series of low-intensity earthquakes or microseisms in the region. A geological fault stretching over 1 kilometer, identified in the area from Plateros to Mixcoac, has been preliminarily linked to the tremors recently felt in this part of the nation’s capital, according to findings released this Friday by the university’s Engineering Institute (II).
The fault, classified as a normal type, was uncovered by UNAM researchers, including Leonardo Ramírez Guzmán, Jorge Aguirre González, and Moisés Contreras Ruiz Esparza, who have been closely monitoring seismic activity in the region. From December 3, 2023, to January 10, 2024, a total of 23 earthquakes with magnitudes ranging from 1.1 to 3.2 were recorded in the Magdalena Contreras and Álvaro Obregón municipalities. These events occurred at depths of less than 1.4 kilometers.
The researchers detailed the fault’s path, starting west of the Periférico Ring and extending through Revolución Avenue, reaching about 300 meters to the east. This surface manifestation of the faulting is currently under thorough examination with various instruments to determine its full extent and depth.
The reactivation of this newly named Plateros-Mixcoac fault is attributed to regional tension accumulation, the sinking of the Valley of Mexico, and aquifer recharge in the Sierra de las Cruces, which serves the metropolitan area. In response to the potential risks posed by these earthquakes, the Seismological Engineering coordination and the Seismic Instrumentation Unit of the II have installed 15 recording stations equipped with sensors to monitor speed and acceleration. These installations have enabled continuous recording of seismic activity from late December 2023 to early February 2024, refining the location of earthquake epicenters previously reported by the National Seismological Service (SSN).
This concerted effort has uncovered a continuous crack over a kilometer long crossing the Mixcoac area, accompanied by permanent soil deformations necessitating further analysis. The findings underscore the fault’s significant impact, extending beyond superficial damage to indicate deeper seismic activity.
The discovery comes amid concerns voiced by residents over the frequent tremors in December and the potential risks they pose. UNAM seismologist Víctor Manuel Cruz Atienza had previously suggested that Mexico City might be experiencing a “swarm of microseisms,” highlighting the ongoing efforts to understand and mitigate the effects of such geological phenomena on the densely populated capital.
