Aug 18, 2014

Taiwan's Sudden Canyon Disappearing in Record Time

Geologic changes tend to happen in slow motion, over millions of years, so when land formations rise and fall over decades, scientists take notice.

The rocks forming the Daan River gorge in Taiwan rose after a 1999 earthquake -- and the gorge is already in danger of disappearing due to the violent and repeated flooding of the river. While earthquakes mix things up in the region every 300-400 years, reports the BBC, the gorge could be gone from erosion in the next 50.

"The really cool thing about this place is that it's happening so fast, we can watch it," said Kristen Cook, a geologist at the German Research Centre for Geosciences told the BBC. "The river can really efficiently remove all of the evidence. We can see processes that you can't reconstruct."

The 1999 Jiji quake raised the rock table about 30 feet -- three stories -- and left a half-mile dam across the Daan river in Western Taiwan.

In 2004, the river ran over the dam, pulling material along which cut a new gorge, which locals refer to as the Grand Canyon of the Daan River, the BBC reports.

"That's one of the exciting things," Cook said. "We expect the process to be the same, but sped up."

As quickly as it came, so it's eroding, about 55 feet a year.

"As the upstream boundary of the gorge keeps moving downstream, the gorge will get shorter and shorter until the upstream boundary reaches the exit of the gorge, and the whole thing is gone," Cook told New Scientist.

From Discovery News

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