Ancient Mesoamerican civilization : A city that was once home to around 90,000 people may have been brought down by centuries of drought, according to a 2015 study.
Researchers found that Cantona, a fortified city in central Mexico, experienced repeated long-term droughts that likely damaged crops and water supplies, contributing to its abandonment between A.D. 900 and A.D. 1050, as per a report.
Scientists investigated why Cantona was abandoned
For years, researchers debated whether climate or cultural changes caused Cantona's decline.
To better understand the city's past, geographers studied sediment cores and water samples from Lake Aljojuca, located about 20 miles (32 kilometers) from Cantona, as per a NBC News report. By analyzing oxygen isotopes and other compounds preserved in the lake sediments, they reconstructed the region's ancient climate.
The results showed that while the area continued to experience wet summers and dry winters, its monsoon seasons were repeatedly disrupted by long-lasting droughts.
A 650-year drought changed the region
The study found that the region endured a 650-year period of frequent droughts from about A.D. 500 to A.D. 1150. The dry spell was part of an even longer drought period that affected Mexico's highlands from about 200 B.C. to A.D. 1300, before the rise of the Aztec Empire, as per the NBC News report.
Researchers concluded that the prolonged lack of rainfall likely reduced water supplies and harmed agriculture, making it increasingly difficult for Cantona's population to remain there.
Drought may have contributed to Cantona's collapse
Lead researcher Tripti Bhattacharya said that, "The decline of Cantonaoccurred during this dry interval, and we conclude that climate change probably played a role, at least towards the end of the city's existence," as quoted by NBC News.
The researchers also noted that Cantona's population actually grew during the early years of the drought. In a 2015 NBC News report, Roger Byrne, an associate professor of geography at the University of California, Berkeley, said, "In a sense the area became important because of the increased frequency of drought," in a statement. "But when the droughts continued on such a scale, the subsistence base for the whole area changed and people just had to leave. The city was abandoned."
