«La impredecibilidad de los microsismos: Explicación de Sheinbaum y un experto en el fenómeno»
Sergio Almazán Esqueda, former president of the Association of Mining, Metallurgical and Geological Engineers of Mexico, spoke about the series of earthquakes and microearthquakes that have been recorded in recent days with their epicenter in Mexico City, something that is not so common. He explained that the earthquake that occurred last night, with a magnitude of 3.00 degrees and its epicenter in the Álvaro Obregón municipality, is due to the fact that it is a seismic country and that only the location of the origin of the earthquake changes.
In an interview with Guadalupe Juárez and Sergio Sarmiento for El Heraldo Media Group, Almazán Esqueda explained that these earthquakes have always occurred, but every day we are more aware and learning from these eventualities in Mexico City.
«It is important to remember that Mexico is a seismic country, because it is affected by five tectonic plates that are continuously shaping the national territory,» he said.
He explained that this causes a large amount of energy to be stored and that the collision of the Cocos Plate with the North American Plate generates the highest number of violent earthquakes in Mexico City and the country in general.
Why didn’t the alarms go off?
The specialist explained that the earthquake last night was felt more in some places than in others and this is due to the proximity to the epicenter. For example, there was a minimal sensation in Cuajimalpa, but in Benito Juárez it was a very significant movement. There are two reasons why the Mexico City alarms did not sound. The first is that it was a 3.0-degree earthquake and therefore the alarms did not perceive it, but the problem is that being the epicenter in Mexico City, it was such an intense activity.
The other cause is that the alert system perceives movements in other parts of the country and thus anticipates what will happen in Mexico City. Depending on how far away the epicenter is, more time will be given to warn of an upcoming earthquake. «For example, in the 2017 earthquake, while the earthquake was happening, the alarm was sounding, this was because the epicenter was in Morelos, 130 kilometers from the capital. But when it is in Oaxaca, it sounds with a minute and a half of anticipation,» he explained.
Claudia Sheinbaum: «It is impossible to anticipate a microearthquake in Mexico City»
The head of government of Mexico City, Claudia Sheinbaum, explained that they are «phenomena that have been happening for a long time, but that have now been formally registered for the first time.» She said that in 2019, a group called Red Ecos was created, which has a specialization branch in microearthquakes that are of low magnitude and have an epicenter in Mexico City.
These microearthquakes are of magnitudes up to 3.6 or 3.8 degrees and are only perceptible in areas very close to the epicenter. She also acknowledged that it is impossible to anticipate an earthquake if the epicenter is Mexico City itself.
«The system is designed to alert distant earthquakes that have their origin in Oaxaca, Guerrero or Michoacán, but it is impossible to know when there will be an earthquake if the origin is in the Valley of Mexico,» she said.
In addition, the head of government of Mexico City reported that tomorrow she will have a meeting with a group of scientists from the microearthquake network, so that they can give a more detailed explanation and all the related information can be transmitted to the citizens.