Scientists now believe that drought was the reason that the Mayan culture was wiped out after appearing so advanced compared to others between 800 and 1000 AD. They believed that changes in annual precipitation may have wiped out the Mayan culture.
The scientists from Cambridge University led by Nick Evans took samples of sediment from the area where Lake Chichancanab was located. They determined that rainfall amounts decreased by up to 70 percent over the course of 200 years. Furthermore, they say that humidity decreased by up to 7 percent.
Scientists used isotopic analysis to study the sediment where Lake Chichancanab was formerly located. They discovered triple oxygen and hydrogen isotope levels during the period when the culture was disappearing. The team looked particularly at water bound molecules in gypsum before making their conclusions. The new findings suggest that people starved to death or were forced to move away from the area because there was not enough water to grow an adequate amount of food.
Up to this point, scientists have looked at many different theories of why the Mayan culture disappeared so quickly about 900 AD. Deforestation and overpopulation have been examined in the past as possible causes.
Scientists say that they are unsure what caused the extreme drought. They say that the time coincides with the Medieval Warm Period where less volcanic ash was found in the atmosphere and increased sunspot activity may have occurred. They also say that massive deforestation may have played a role in decreasing the amount of moisture in the air.
Other questions still remain to be answered about the demise of the Mayan culture. Some wonder how many people were wiped out while others suggest that small groups banded together and traveled to other areas instead of living in a larger unit. Others believe that most people stayed in the region, but they became busy trying to survive instead of advancing civilization as they had when water was more abundant.