Treee ring dating
The graph shows correlations to spikes at 5,200 BC, 8,800 BC, 12,400 BC, c. But the northern cores show the activity beginning 1644 BC.The evidence for the 5200 BC event is strong in the Dome C core. 20, 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.The Wide-field Infrared Survey Explorer, or WISE, spacecraft will employ an infrared camera to detect light- and heat-emitting objects that other orbiting telescopes, such as the Hubble, might miss. It's well known that magnetic poles wonder and have changed in the past...."We can help protect our Earth by learning more about the diversity of potentially hazardous asteroids and comets," said Amy Mainzer, deputy project scientist for the 0 million mission at NASA's Jet Propulsion Laboratory in Pasadena, California. This would give some meaning to why African plains were once green and lush and now are more akin to deserts. I don't see how this could all have happened over night.
"The latter was very severe, ruining ancient civilizations and socio-economic systems," the researchers wrote.
The Terra Papers (linked in my sig) suggests that at some time - 5,000ish or less years ago, maybe - maybe earlier...