It represents the governors of 30 oil and gas producing states. Now, new research shows cycles of solar intensity brought on droughts that influenced Mayan culture and in the end may have wiped it out entirely. A team of researchers led by University of Florida geologist David Hodell reports finding that the Yucatan Peninsula suffered recurrent droughts linked in time to a cyclical brightening of the sun. In 1995, Hodell and two colleagues at University of Florida published results in the journal Nature suggesting that the 9th century collapse of the Maya civilization may have been influenced by a severe drought that lasted for more than 150 years. The paper was based on analysis of a sediment core from Lake Chichancanab on the north central Yucatan Peninsula.
Cores are samples of lake sediment retrieved by driving a hollow tube into the lake bottom.
The sediments are deposited layer by layer providing a timeline that allows researchers to see a continuous record of changes in climate, vegetation and land use. For the latest research, Hodell and colleagues returned to the lake to collect a fresh series of cores. Lake Chichancanab s water is nearly saturated with gypsum, and the cores show layers of gypsum concentrated at certain levels. The researchers found that the the gypsum deposits were laid down in a cyclical pattern, once every 208 years. The 208 year cycle is nearly identical to a known 206 year cycle in solar intensity, Hodell said.