Reviewed by Doug Brown
Beginning with the earliest surveys in the 1800s, geologists noticed there was something odd about eastern Washington. The term "scablands" was used to describe the landscape, which appeared to be covered with gaping wounds that went down to the bedrock. The prevailing assumption was that either the Columbia River had sculpted the landscape by shifting its course over the millennia, or that glacier ice had carved it.
Then in the 1920s, a headstrong geologist from the University of Chicago took a couple of trips to survey the scablands. J Harlen Bretz (no period on the J -- his first name was actually Harley but he liked the sound of J Harlen) measured vast coulees and canyons, saw evidence of ancient waterfalls that dwarfed Niagara, and reached a radical conclusion. Soennichsen's accessible book begins with an imagining of Bretz sitting on a bluff in the scablands, loading his pipe and double-checking his calculations as his graduate students toss rocks off the bluff into the water below. The inescapable conclusion was that water, not ice, had carved out the scablands, now dubbed by Bretz the "channeled scablands." And not water from some measly little river like the Columbia -- there was evidence of flood bars over 600 feet high. An almost inconceivable amount of water had torn through eastern Washington, stripping the land down to the basaltic bedrock and then scouring into the basalt itself. Bretz found evidence of the flood all the way down the channel of the Columbia, particularly in the Gorge. The Willamette Valley still contains large boulders rafted here on ice from the Canadian Rockies.
Bretz knew this flew in the face of dogma, and not just regarding the origin of the scablands. In geology, the concept of uniformitarianism held sway at the time. This idea had arisen in the 1800s as a response to "catastrophism," which at the time meant trying to explain most geological features as having been caused by Noah's flood. Uniformitarianism held that geologic processes today were the same as those from the past. It was a way to break from the religious dogma of a young Earth and begin seeing what John McPhee later poetically called "deep time." Given enough time, a river really can carve a grand canyon just by flowing the way it is today, as the Colorado did. Yet here was Bretz invoking passe catastrophism, even though he backed it up with an impressive amount of field observation and calculation.
He published a couple of papers that met with less response than he had hoped for. Then he received an invitation to present his work at the Cosmos Club in Washington, D.C. For a scientist, this was the equivalent of a musician being invited to play in Carnegie Hall. Bretz didn't realize until too late it was an ambush. All the top geologists were present, and after his talk, they rose one at a time to tell him how totally wrong he was. Men who had never been to Washington state told Bretz that it was obvious the scablands were caused by rivers, or ice, or ice and rivers. Bretz was completely demoralized, but after several months he pulled himself up and decided to address the contrary theories. He wrote to the men who had been at the Cosmos Club and asked them to clarify their positions or confirm objections they had stated, only to find that many claimed not to remember saying what they had said. He published that paper, and then a few others summarizing all of the evidence he had amassed. Over time, geologists began going to the channeled scablands themselves and seeing the inescapable. Bretz fortunately lived long enough to be vindicated.
Soennichsen's book is in a sense three stories: the story of Bretz's life, the story of the floods, and the story of the long road Bretz's theory took to final acceptance. The biography elements of the book are well-fleshed out, as Soennichsen had plentiful access to family members as well as colleagues. The story of how a glacier dammed the north fork of the Clark River to create glacial Lake Missoula, and what happened when that dam broke is vividly described. We learn the story along with Bretz as he makes his observations. Bretz's Flood is a wonderful addition to the geology of the Pacific Northwest, recommended to anyone living here (and to geologists everywhere).
Books mentioned in this post