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A great part of Britain’s identity is wrapped up in the fact that it’s a part of Europe, but it stands apart, quite literally, as an island. According to new sonar studies of the Channel which runs between Britain and France, that wasn’t always the case. Until about 200,000 years ago, Britain was a peninsula of Europe, and could be walked to from mainland France — as many early humans did. So what severed the soil? An almost unimaginably huge flood, possibly triggered by a small earthquake, pushed a giant, river-fed lake through the narrow isthmus which once stood where the English Channel now flows; then, the proverbial dam broke. At its peak, the flood may have discharged up to a million cubic meters of water per second, making it one of the most significant known megafloods in the Earth’s history.
To Pacific Northwesterners in the know, this may sound a bit familiar: the beautiful Columbia River Gorge which separates Oregon and Washington wasn’t there a few hundred thousand years ago, either. The end of an ice age sent huge amounts of rocky glacier meltwater cascading (no pun intended) from eastern Washington toward the sea, and with it, it took some really significant chunks of what was then simply the Cascade mountain range. Which is why the Gorge boasts some of the highest and most impressive waterfalls in the country; until that precipitous flood, those were rivers flowing through a more or less uninterrupted mountain range! At its height, the waters were over 1,000 feet deep, moved at more than 90 miles per hour and carrying house-sized boulders. Perfect for a little x-treme tubing, ice age style.
“An almost unimaginably huge flood” Eh?
sounds Biblical.
posted by NepentheSea on 7-19-2007 at 7:29 am
“the beautiful Columbia River Gorge which separates Oregon and Washington wasn’t there a few hundred thousand years ago”
Err, no.
The Columbia River is over 20 million years old. It predates the Cascade Mountains, and the Gorge was cut by the river as the mountains rose.
The Missoula Floods made the Gorge wider, but not much deeper. The Floods took the route they did because the Gorge was already there.
posted by Dick on 7-19-2007 at 10:12 am
Wasn’t the strait of Gibralter supposed to have been the site of a massive waterfall or flood or something? Like the Mediterranean was a lake until “boom”?
Rich
posted by Rich on 7-19-2007 at 12:45 pm
I’ll mention the Black Sea deluge. Explorers have found entire well preserved villages beneath the Black Sea. The widely accepted hypothesis is that the deluge buried them and then preserved them in a low oxygen environment.
posted by n2y2 on 7-19-2007 at 4:17 pm
The Black Canyon, near Twin Falls, ID was cut to a depth of nearly 400 meters thru earlier lava flows (basalt) when Lake Bonneville sprang a leak - a BIG one. The gorge took less than a year to excavate, unlike its cousin to the south, the Grand Canyon of Arizona.
posted by Doc on 7-19-2007 at 6:13 pm
The geography of the Columbia River Gorge also created Celilo Falls, which was home to one of the longest continuously inhabited areas known. People lived and fished at the falls for more than 10,000 years. The falls and the village were flooded when the gates closed at The Dalles Dam in 1957. The falls are on the East end of the Gorge. It is an interesting story worth learning about.
posted by Orygun on 10-9-2008 at 10:22 am