The Missoula floods
An ice dam fails dozens of times, and each failure scours the landscape of eastern Washington.
- When
- —
- Duration
- 2 thousand years
- Known to
- ± 1 thousand years
- Era
- Late Pleistocene, Quaternary
Glacial Lake Missoula, dammed by a lobe of the Cordilleran ice sheet, repeatedly bursts between about 15,000 and 13,000 years ago, releasing volumes comparable to Lake Erie in a matter of days at flows greater than all the world's rivers combined. The result is the Channeled Scablands — a landscape of giant dry cataracts, house-sized boulders and ripple marks ten metres high. J Harlen Bretz proposed a catastrophic flood origin in the 1920s and was ridiculed for forty years before being vindicated.