January 20, 2009

Nature Lead Early Civilization To Leave Peru

Researchers say that nature lashed out against civilization 3,600 years ago, by using earthquakes and floods, followed by blowing sand, which drove away residents of an area that is now in Peru.

"This maritime farming community had been successful for over 2,000 years, they had no incentive to change, and then all of a sudden, boom, they just got the props knocked out from under them," anthropologist Mike Moseley of the University of Florida said in a statement.

Moseley and other colleagues studied civilization of the Supe Valley along the Peruvian coast, which was established about 5,800 years ago.

The researchers reported in Tuesday's edition of Proceedings of the National Academy of Sciences, that the people thrived on land adjacent to productive bays and estuaries. 

Ruth Shady, a Peruvian archaeologist, suggests that the Supe fished with nets, irrigated fruit orchards and grew cotton and a variety of vegetables.  They also built extremely large and elaborate stone pyramid temples, thousands of years before pyramids were built by the Maya.

After studying the region, researchers think they know why the Supe disappeared about 3,600 years ago.

The researchers found that a massive earthquake struck the seismically active region, collapsing walls and floors and creating landslides from barren mountain ranges surrounding the valley. 

In addition, layers of silt indicate massive flooding followed.

Then, after all of these events, El Nino came along with a periodic change in winds and currents in the Pacific Ocean, and brought heavy rains that damaged irrigation systems and washed debris into the streams and down to the ocean, where the sand and silt settled into a large ridge, sealing off the previously rich coastal bays.

The researchers concluded that in the end, the land where the Supe lived for centuries became uninhabitable and their society collapsed. 

The Supe's demise may hold a cautionary tale for modern times for much of the world's population centers built in environmentally vulnerable areas, the researchers said.  El Nino events might become more common as global climate change continues.

"These are processes that continue into the present," said Dan Sandweiss, the paper's lead author and an anthropology professor and graduate dean at the University of Maine.

The study was funded by the University of Florida and the Heyerdahl Exploration Fund, University of Maine.


On the Net: