Clues behind the extinction of the Maya civilization sometime in the 8th or 9th centuries were recently uncovered by a researcher team led by Andre Droxler, an Earth scientist at Rice University. According to the study, the unexpected disappearance of the sophisticated civilization of over 19 million people could have been due to two 100-year-long droughts.
To conduct the study, researchers gathered sediment from the famous Great Blue Hole in Belize and the Rhomboid Reef to analyze its chemical composition. The team drilled into the core to uncover sediment deposited there over hundreds of years. What the sediment revealed was two prolonged droughts in the area of the Yucatan that was once the Mayan heartland, separated by about 200 years and lasting about a century each. While this was not the first study to suggest drought as the cause of the mysterious disappearance of the Maya civilization, it is the first study to present clear, physical evidence in support of the theory.
The sediment, researchers say, is deposited in the lagoon in a thin layer during periods of storm and heavy rainfall when the runoff from streams and rivers tops the retaining walls to settle in the lagoon. Droxler calls the phenomenon to a “sediment trap.” During periods of heavy rain, aluminum and titanium are stripped away from volcanic rock on the surface and carried to the ocean, settling in sediment traps like the one in the Great Blue Hole.
By testing the chemical composition of the sediment core in these areas, scientists are capable of determining the amount of rainfall during certain periods by uncovering the levels of aluminum and titanium within. A dip in the metals during the periods when the great civilization vanished from the area points to drought as a probable cause of the disappearance.
According to the researchers, the civilization relocated to the North following the first drought, but returned to the area once the rains began again only to be completely lost from the records following the second major drought. The Mayan people never went completely extinct, as Mayan ancestry can be found across the Americas, though the sophisticated and iconic civilization disappeared almost without a trace. The theory that severe drought could be the reason the Maya civilization vanished has been prominent since at least 1995, reports Live Science.
Two studies published in Smithsonian Magazine in 2012 also suggested that massive deforestation coupled with low rainfall could have led to environmental devastation capable of forcing the Mayans from their elaborate cities. Analyzing archaeological data across the areas of the Yucatan once inhabited by the Maya civilization, researchers from Arizona State University found that the agricultural demands and heavy use of wood for ornate cityscapes fueled rapid forest clearing and coincided with the low periods of rainfall, suggesting that deforestation may have played a part in the drought.
Basing their study off these trends, researchers at Columbia University applied quantitative data to the study’s findings to determine how deforestation may have affected rainfall. To do this, the researchers applied measurements of cleared and forested lands and population records to a computer model and ran simulations to uncover what effects the Maya civilization’s heavy dependence on wood may have had to its disappearance from the area. Both studies lent merit to the theory that drought was the culprit in the mystery of the Maya civilization, but substantial physical evidence had not yet been found.
By Sree Aatmaa Khalsa