For hundreds of years the Mayans dominated large parts of the Americas until, mysteriously in the 8th and 9th century AD, a large chunk of the Mayan civilisation collapsed.
The reason for this collapse has been hotly debated, but now scientists say they might have an answer - an intense drought that lasted a century.
Studies of sediments in the Great Blue Hole in Belize suggest a lack of rains caused the disintegration of the Mayan civilisation, and a second dry spell forced them to relocate elsewhere.
* * *
Dr Droxler’s research involved drilling cores from sediments in the Great Blue Hole, a vast circular sinkhole off the coast of Belize that is 984 feet (300m) across and 407ft (124m) deep.
The hole formed tens of thousands of years ago when sea levels were much lower, being filled as the oceans began to rise.
Ongoing sedimentation at the base of the hole allows scientists to study periods from history.
When there are storms or extremely wet periods, more sediments are deposited at the bottom of the lagoon.
But less rainfall can also be accounted for, in particular due to the ratio of titanium to aluminium in cores taken from the sediment.
A lower ratio of titanium to aluminium corresponds to dryer periods.
* * *
With his team he found that from 800 to 1000 AD, no more than two tropical cyclones occurred every two decades, when usually there were up to six.
This suggests major droughts occurred in these years, possibly leading to famines and unrest among the Mayan people.
And they also found that a second drought hit from 1000 to 1100 AD, corresponding to the time that the Mayan city of Chichén Itzá collapsed.
The research adds to previous evidence that suggested decreased rainfall coincided with a decline of Mayan culture.(Full article at the Daily Mail)
No comments:
Post a Comment