Want to Super Size That?

Steve's picture

I hear that the Mayor of New York wants to ban Super Size sodas in the City.  Seems silly to me, but just maybe he will get his way. When it comes to Super Size natural disasters however, even the Mayor of the Big Apple can’t dictate terms.

I’ve blogged about dam break floods several times now --  What do you say if we Super Size That?

Way back in the last ice age, about 15,000 years ago, a huge ice sheet moved down from Canada and covered parts of many northern States. At one place near the Idaho-Montana border, the ice sheet blocked the Clark Fork River at a gap where it flowed westward through the continental divide. This Super Size dam towered hundreds of meters.  With nowhere to go, water coming down the river behind the blockage backed up for several 100 km on the east side of the divide. Glacial Lake Missoula grew and grew, eventually rivaling Lake Huron in volume.



You can guess what happened sooner or later --- the ice dam broke and all that stored water poured through the gap in a horrific flood. Try to imagine 35,000 Niagara Falls! Lake Missoula drained in about five days and its wake deeply eroded a large section of central Washington State. The scoured area appropriately, is named “The Scablands”. Farther down stream at narrows of the Columbia River, transient lakes formed 225 meters deep and equal in size to Lake Ontario.  Even the Willamette and Tualatin Valleys of Oregon, 700 km from the dam, drown for days.

I figure that if the Flood of Glacial Lake Missoula happened today, some 3,000,000 people would get wet.  That’s one “Big Gulp” that even I would be happy to ban.

Steven N. Ward   Santa Cruz

Risk Alert