Submitted via IRC for BoyceMagooglyMonkey
The ancient Maya were an innovative people. They constructed intricate cities throughout the tropical lowlands of the Yucatán Peninsula, communicated using one of the world's first written languages, and created two calendar systems by studying the stars. But despite their achievements, the thriving Mayan civilization mysteriously collapsed sometime between the eighth and ninth centuries. We still don't know exactly why.
The general consensus is that the Mayan collapse was caused by a number of things, including disease, war, and other sociopolitical conflicts. One natural factor may have contributed to all of these issues: drought. A particularly bad drought would have made it difficult for the Maya to collect enough drinking water and to irrigate their crops. It also could have encouraged the spread of disease and increased the strain between Mayan leaders and their people.
[...] 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. When the drought was most severe, rainfall plummeted by as much as 70 percent, the researchers wrote in their study published Thursday in Science.
The team developed a method to extract that thousand-year-old water [trapped in lake bottom sediment's gypsum] and study the hydrogen and oxygen isotopes inside. During drought conditions, lighter water isotopes evaporate first, and the heavier isotopes are left to be trapped in gypsum. By tallying when those heavy isotopes were more common, the researchers were able to create rainfall and humidity estimates.
[...] It could even tell us about the climate histories of other planets: Mars, for instance, also has gypsum deposits.
Source: https://gizmodo.com/scientists-just-measured-the-drought-that-may-have-brou-1828053642
(Score: 0) by Anonymous Coward on Monday August 06 2018, @08:47AM
And then there also was 535 AD: https://www.youtube.com/watch?v=cKUz5Vjq9-s [youtube.com]