On the morning of Sunday, October 20, a micro seismic event of magnitude 2.6 shook Ixtapaluca, State of Mexico, being the second such event recorded in the Valley of Mexico throughout the day. Fortunately, no damage or injuries were reported due to this tremor.
The National Seismological Service indicated that the epicenter of this micro seismic event was located 3 kilometers southeast of Ixtapaluca and occurred at 5:44 AM that Sunday. However, the official confirmation was issued almost four hours after the event. This phenomenon was added to another micro seismic event detected earlier in the Coyoacán borough, which had a magnitude of 1.5 and was recorded around 4:33 AM at a depth of one kilometer.
The second seismic event occurred next to Parque de los Venados, in the area bordering Coyoacán and Benito Juárez. These boroughs have experienced multiple micro seismic events of lesser magnitude throughout the year. In the neighborhoods near the epicenter of the micro seismic event in Coyoacán, a “strong” perception was reported despite its low magnitude.
In situations like this, it is important to remember why the seismic alert does not sound during micro seismic events. Both the Government of Mexico City and the National Seismological Service explain that the seismic alert is activated to take precautions and seek shelter upon perceiving a seismic event coming from other regions that begins to be felt in the Valley of Mexico.
In the case of micro seismic events, having their epicenter closer, the seismic alert is not issued, as the system is designed to anticipate significantly larger quakes. Therefore, during these lower intensity events, the speakers in Mexico City remain inactive.