posted on Mar, 14 2003 @ 04:36 PM
A study of southern Caribbean sediments suggests that a centurylong dry spell may have been the killing blow in the demise of the Mayan civilization
that once built pyramids and elaborate cities in Mexico.
Konrad A. Hughen, a geochemist at the Woods Hole Oceanographic Institution, said sediments from the Cariaco Basin in northern Venezuela clearly record
a long dry siege that struck the entire Caribbean starting in about the seventh century and lasting more than 100 years.
Within this dry period, said Hughen, there were years of virtually no rainfall. It was in those periods of extra dryness, he said, that the Mayan
civilization went through a series of collapses before its final demise. Hughen is co-author of a study appearing Friday in the journal Science.
Hughen said the Maya flourished in what is known as the pre-classic period before 700 A.D., building cities and elaborate irrigation systems to
support a population that soared above a million. The civilization collapsed and many of the sites were abandoned early in the 800s. They were later
reoccupied only to collapse again, with some cities deserted in 860 and others in 910.
"Those abandonments occur synchronously with the timing of the droughts in our record (from the sediments), suggesting the droughts were causing
those events," said Hughen.
The sediment records show that the gradual drying started about 1,200 years ago, but there was still enough rain for the Mayans to flourish.
Mayan communities in the southern and central lowlands collapsed first, while those in the northern highlands lasted for another century before the
"The northern areas had access to more ground water resources," said Hughen. "They were able to weather the first and second dry periods, but not
T. Patrick Culbert, a professor emeritus at the University of Arizona and a noted authority on the Mayan culture, said the climate study offers a
plausible explanation of what happened to the Mayans.
"They were so vulnerable that anything could have knocked them over," said Culbert. "If there were these severe droughts, it would have been a
disaster for them."