Eruption Refugees

　The biggest cause is the influx of eruption refugees. Everything I've read confirms this.

　Mexico, including its central plateau, is a nest of volcanoes. Generally speaking, a single volcanic eruption occurs multiple times, so it is not easy to verify the age of the eruptions, but they did cause some notable disasters.

　200 BC - 50 AD... Multiple eruptions of Popocatepetl.

　70 AD...A large eruption of Popocatepetl causes a large amount of pumice to fall.

　115 AD... Chichinautzin eruption.

　275 AD... A large lava flow from the Xitle volcano to Cuicuilco.

　Although no detailed reports seem to have been made, it seems that eruptions of various sizes occurred almost constantly. It appears that the affected areas varied depending on the wind direction at the time of the eruption. It seems that it was natural for people to live their lives worrying about changes in the mountains.

　The Popocatepetl volcano had a major indirect impact on Teotihuacan. The earliest evidence of an eruption dates back 200,000 years, with intermittent records of volcanic ash. During a major eruption that is thought to have occurred in 70 AD, volcanic ash was carried by southwest winds, causing pumice 1 to 3 meters thick to fall over a wide area.

　Excavation reports of the Tetimpa village located in the middle of Cholula and Popocatepetl volcanoes are available online. It was probably a single-family residential complex, with the largest building at the back of a small plaza, flanked by sleeping quarters and cooking houses, similar to the later "three-temple structure" of Teotihuacan. The upper structure was made of mud and branches, but the design of the stone pedestal closely resembles Teotihuacan's Talud-Tablero architectural style. In the center of the square is a hearth with a statue imitating a volcano, which looks like a "central altar."

　It is widely said that the "three-temple structure'' or "Talud-Tablero architectural style'' can be found throughout most of Mesoamerica before 1 AD. It seems that it was not original to Teotihuacan.

　It is said that many farming villages northeast of the volcano have been abandoned. Where did the farmers move?

　Perhaps due to the wind direction, Cholula has no record of ash falling at this time. Cholula maintained its image as a "chosen sacred place." I don't think that there were zero people migrating there, but it seems that a location with a close view of the Popocatepetl volcano, which continues to emit smoke, is a difficult choice.

　↑at Cholula Regional Museum.

　It is believed that many wanted to move to the Teotihuacan Valley, where the damage caused by the eruption was not previously remembered.