Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Earthquakes, El Ninos fatal to earliest civilization in Americas

21.01.2009
First came the earthquakes, then the torrential rains. But the relentless march of sand across once fertile fields and bays, a process set in motion by the quakes and flooding, is probably what did in America's earliest civilization.

So concludes a group of anthropologists in a new assessment of the demise of the coastal Peruvian people who built the earliest, largest structures in North or South America before disappearing in the space of a few generations more than 3,600 years ago.

"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,'" said Mike Moseley, a distinguished professor of anthropology at the University of Florida. "They just got the props knocked out from under them."

Moseley is one of five authors of a paper set to appear next week in the online edition of the Proceedings of the National Academy of Sciences.

The people of the Supe Valley along the central Peruvian coast did not use pottery or weave cloth in the settlements they founded as far back as 5,800 years ago. But they flourished in the arid desert plain adjacent to productive bays and estuaries. They fished with nets, irrigated fruit orchards, and grew cotton and a variety of vegetables, according to evidence in the region unearthed by Ruth Shady, a Peruvian archaeologist and co-author of the paper. As director of the Caral-Supe Special Archaeological Project, Shady currently has seven sites in the region under excavation.

Most impressively, the Supe built extremely large, elaborate, stone pyramid temples -- thousands of years before the better-known pyramids crafted by the Maya.

"They're impressive, enormous monuments," Moseley said.

The largest so far excavated, the Pirámide Mayor at inland settlement Caral, measured more than 550 feet long, nearly 500 feet wide and rose in a series of steps nearly 100 feet high. Walled courts, rooms and corridors covered the flat summit.

The Supe seemed to thrive in the valley for about 2,000 years. But around 3,600 years ago, an enormous earthquake -- Moseley estimates its magnitude at 8 or higher -- or series of earthquakes struck Caral and a nearby coastal settlement, Aspero, the archaeologist found. With two major plates scraping together not far offshore, the region remains one of the most seismically active in the world.

The earthquake collapsed walls and floors atop the Pirámide Mayor and caused part of it to crumble into a landslide of rocks, mud and construction materials. Smaller temples at Aspero were also heavily damaged, and there was also significant flooding there, an event recorded in thin layers of silt unearthed by the archaeologists.

But the flooding and temples' physical destruction was just the dramatic opening scene in what proved to be a much more devastating series of events, Moseley said.

The earthquake destabilized the barren mountain ranges surrounding the valley, sending massive amounts of debris crashing into the foothills. Subsequent El Niños brought huge rains, washing the debris into the ocean. There, a strong current flowing parallel to the shore re-deposited the sand and silt in the form of a large ridge known today as the Medio Mundo. The ridge sealed off the formerly rich coastal bays, which rapidly filled with sand.

Strong ever-present onshore winds resulted in "massive sand sheets that blew inland on the constant, strong, onshore breeze and swamped the irrigation systems and agricultural fields," the paper says. Not only that, but the windblown sand had a blasting effect that would have made daily life all but impossible, Moseley said.

The bottom line: What had for centuries been a productive, if arid, region became all but uninhabitable in the span of just a handful of generations. The Supe society withered and eventually collapsed, replaced only gradually later on -- by societies that relied on the much more modern arts of pottery and weaving, Moseley said.

With much of the world's population centers built in environmentally vulnerable areas, the Supe's demise may hold a cautionary tale for modern times, the researchers said. El Niño events, in particular, may 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.

Affirmed Moseley, "You would like to say that people learn from their mistakes, but that's not the case."

The other authors of the paper are David Keefer, a geologist and geoarchaeologist with the University of Maine's Climate Change Institute, and Charles Ortloff, a consulting engineer who has spent the past three decades working in the Andes.

Michael Moseley | EurekAlert!
Further information:
http://www.ufl.edu

More articles from Earth Sciences:

nachricht Arctic melt ponds form when meltwater clogs ice pores
24.01.2017 | University of Utah

nachricht New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists spin artificial silk from whey protein

X-ray study throws light on key process for production

A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Breaking the optical bandwidth record of stable pulsed lasers

24.01.2017 | Physics and Astronomy

Choreographing the microRNA-target dance

24.01.2017 | Life Sciences

Spanish scientists create a 3-D bioprinter to print human skin

24.01.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>