From Popular Mechanics
With
over 4 trillion gallons of rushing water, it was a flood of biblical
proportions. Villages for miles around were swallowed in a single,
violent gulp. Yet a king arose out of the destructive floodwaters. By
dredging of the flooded lands, he founded the Xia dynasty that would
live on centuries. At least, that's how the epic Chinese legend goes.
And today scientists have found the first proof that this ancient Chinese legend is true.
A
team of archaeologists and geographers, led by Qinglong Wu at Peking
University, in Beijing, China has discovered sedimentary evidence that
the Chinese 'Great Flood' really did happen. In roughly 1920 BC-as China
was transitioning from the neolithic era to the bronze age-an enormous
flood on the Yellow River barreled down a corridor now known as the
Jishi Gorge, into the Guanting Basin in central China. Wu and his
colleagues describe their discovery today in the journal Science.
To
understand how Wu's team discovered the fingerprints of the 4 trillion
gallon flood, you have to know how a such a disaster could have even
arisen in the first place.
Around
4000 years ago, an earthquake rumbled through central China, creating a
massive landslide in deep, narrow valley with rocky, steep sides. That
landslide corked up the gorge, forming a pyramid-like dam of rock and
dirt that blocked the Yellow River. Wu's team believes that for
somewhere between 6 to 9 months, that dam held. As the riverbed
downstream turned dry, a tenuous lake of 4 cubic miles of water-half the
size of Lake Mead behind the Hoover Dam-was growing.
The whole thing broke, releasing a horrific torrent of destruction.
But,
as the rising lakewater eventually spilled over the new dam, it wasn't
just a trickle. The whole thing broke, releasing a horrific torrent of
destruction. "It's among the largest known floods to have happened on
earth during the past 10,000 years. And it's more than 500 times larger
than a flood we might expect on the Yellow River from a massive
rainfall," says Darryl Granger-a geologist at Purdue University in
Lafayette, Indiana-with the research team.
Wu's
team pieced together this history by carbon dating two different types
of soil samples. The first were samples taken from downstream, samples
of what was once the ancient earthen dam. These were collected as far
away as 15 miles down, including at an ancient settlement, which also
has one of the earliest known remnants of noodles. That was instrumental
in estimating the size of the ancient flood. "By identifying those
sediments, and carefully surveying their locations, on both sides of the
valley, we were able to find out the dimensions of that flood channel,
so the size of it and the shape of it, and exactly how high the flood
waters reached," Granger.
The
second type of sample was taken from the remnants of the ancient dam
itself. Although the dam broke around 4,000 years ago, not all of the
dirt and soil that made it up was swept away. The lowest part of the dam
is still buried under part of the Yellow river. Wu's team came across
this strange sediment in 2008, and when they compared it with downstream
dirt, realized what they had found.
Together
these two types of samples let Wu's team piece together the history,
creating fact out of a truly awesome event once thought to be little
more than legend.
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