Chichancanab

By analyzing sediment from Lake Chichancanab in the Yucatán Peninsula, Gázquez-Sánchez and his colleagues found that compared to today, annual rainfall decreased by between 41 percent and 54 percent over the multi-decade Mayan drought.

Using a new geochemical method to measure the water locked within gypsum from Chichancanab, the researchers have built a complete model of hydrological conditions during the terminal Classic Period when the Maya collapsed.