Monday, January 01, 2018

Dry Falls

Photo 5/12/17
This is in Dry Falls State Park, WA. Shrub-steppe habitat. At the head of Lower Grand Coulee, a large canyon without a river.
This, as far as we know, was the largest waterfall on earth, 3.5 miles wide. 
The broad valley with dry falls was formed when the ice dams at the south end of the Cordilleran ice sheet broke, draining Glacial Lakes Missoula and Columbia, at one time rivalling Lake Michigan in size. There may have been 25 or more of these Missoula Floods. The wall of water is estimated to have been 300 feet high, travelling at 65 miles per hour, an intensity required to move the garage-sized boulders downstream. The floodwaters filled the Willamette Valley, depositing rich Palouse Silt, before exiting at Wallula Gap, the chaos giving rise to millions of apples. This is how the earth farms itself. 

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