Where is the Acambay fault and why it could be causing microseisms in Naucalpan, Edomex

This is the area where the Acambay fault is located | Photo: Jovani Pérez – Infobae Mexico

Residents of the Praderas de San Mateo neighborhood, located in the municipality of Naucalpan, in the State of Mexico, have reported a series of micro-earthquakes that have occurred in recent weeks, causing structural damage to several homes. Since July 18, neighbors began to hear loud noises that resembled explosions, raising concerns about the origin of these phenomena. What is known so far?

To clarify the cause of these tremors, the authorities installed a seismograph in the area, whose installation has recently been completed. The telluric movements were attributed to a rearrangement of the Acambay Fault, which passes through the region and part of the Gustavo A. Madero municipality in the north of Mexico City; however, it is notable that in Gustavo A. Madero no microseisms have been reported, which has led the affected neighbors to question this theory.

The official explanation for these microseisms has been met with skepticism by the community. Residents of Praderas de San Mateo have suggested that the noises could be related to the use of dynamite in the construction of a new apartment complex nearby. This theory has gained strength because the explosions and seismic movements only occur from Tuesday to Friday, aligning with the typical work schedules of construction companies. While this is being defined, where exactly is the Acambay fault?

Residents of the Praderas de San Mateo neighborhood have reported damage to their homes as a result of the earthquakes. Credit: Cuartoscuro

The Acambay Fault, presumed responsible for the microseisms in Naucalpan, is an active geological fault located in central Mexico and which crosses the State of Mexico in a northwest-southeast direction for about 50 kilometers, also encompassing entities such as: Querétaro, Hidalgo and Guanajuato. More specifically, it extends from the municipality of Acambay, passing near the towns of:

• Temascalcingo
• Atlacomulco
• Jilotepec
• Jocotitlan Volcano

Experts in the field have pointed out that this geological fault can be considered a normal fault, although with a left lateral component, meaning that the block of rock located above the fault moves downwards in relation to the block of rock below, with a lateral movement to the left.

In terms of activity, the Acambay fault is considered active with significant seismic potential. Although it has not generated large-magnitude earthquakes in recent times, moderate-intensity earthquakes have been recorded along its path, such as those reported since July 18 and which returned on the 30th of the same month.

In this regard, it has been reported that it represents a considerable risk, in terms of strong earthquakes, for nearby populations, including those located in the municipalities of Acambay, Atlacomulco and Temascalcingo, due to its potential to generate telluric movements and the vulnerability of the structures in the region.

Authorities confirmed the installation of a seismograph in the region Credit: Cuartoscuro

The Acambay Fault is therefore and has been the subject of constant study by geologists and institutions such as the National Seismological Service (SSN) of Mexico or the Geology Institute of the National Autonomous University of Mexico (UNAM), institutions that seek to better understand its behavior and thereby evaluate the seismic risk it represents for the region.

It is worth remembering that last Tuesday, August 13, it was announced that the installation of a seismograph in Praderas de San Mateo, Naucalpan, had been successfully completed, according to an update by the Institute of Geological and Atmospheric Research A.C. This progress, it was said, will allow better monitoring of the telluric movement in the region. On social media, the institution announced: “A seismograph has been placed in Praderas de San Mateo, Naucalpan, which will help clarify the origin of the earthquakes that have been recorded in the area.” In addition, they invited the public to review all the updates of their studies on their website and to follow the live broadcast of the monitoring.

Seismograph installation in Naucalpan concludes | Photo: X @IIGEAac

The platform not only provides real-time monitoring of seismic activity, but also a form for citizens to report structural damage to their properties. This is relevant because, as mentioned on social media, not only can cracks be repaired, but Civil Protection should also assess the safety of the reported properties. “Do you have damage to your home? Fill out the following form,” the online platform highlights to facilitate reporting any damage resulting from earthquakes.

Monitoring is a vital tool to better understand the seismic phenomena affecting Naucalpan. The platform assured that its updates will be constant and accessible to the general public.