Its grim black walls of basalt frown across a broken chain of linear lakes, some of them as wide as the coulee floor. ......potholes a hundred feet deep in rock, dry cataracts one hundred to four hundred feet high, and river bars one hundred to two hundred feet thick. ....under the present semiarid climate it lies naked of forest mantle, every detail of its form clearly displayed.
--J Harlen Bretz, 1932
The Grand Coulee, which envelops Sun Lakes-Dry Falls State Park, is the kind of biblically-proportioned landscape that engenders a strong emotional response every time I enter. Even without the perspective of a geological education, there is something so strong and profound about this place....
The park is popular, especially so in the amped-up post-pandemic surge in outdoor recreation. With nearly 40% of the park's area designated for preservation without roads or development, though, the wide-open spaces yielded ample solitude for Patty and I as we explored the nuances of its cliffs and coulees this past May.
100 years ago, a geology professor from the University of Chicago, J Harlen Bretz, sought out this place.
His curiosity had been piqued by a USGS topo map he had seen a decade earlier, showing a wide, deep coulee that contained no river that could have carved it. Since the 1820's, geologists had developed their discipline on the foundational belief (uniformitarianism) that landforms and deposits on the earth's surface had formed over long periods of time, by ordinary, observable, continuous processes-- "the present is the key to the past." Absent a river, what force carved the Grand Coulee?
For eight summers, Bretz traveled from his home in Chicago to the "scablands" of eastern Washington with his wife, two young kids, the family dog and a few college students. He became convinced that neither stream nor glacial erosion had sculpted this landscape. His evidence was the presence of these unusual features:
huge dry channels (coulees), hundreds of feet deep, with rippled beds of coarse gravel
blades of resistant bedrock remaining inside the channels
plateaus stripped down to bare basalt
massive granite boulders scattered far from a bedrock source
circular potholes in the basalt surfaces
dry cataracts, up to 5 times the width of Niagara Falls
In his memoir he recalled, "I could conceive of no geological process of erosion to make this
topography except huge, violent rivers of glacial meltwater." Of course, that catastrophic solution ran counter to the prevailing uniformitarian principle. What ensued was one of the great scientific debates of the 20th century.
Patty and I set up camp under the cotton-shedding Bigtooth Aspen trees that provide shade in the older loops of the park campground (luckily, we had secured a reservation a couple of months earlier), then ventured out on the Boy Scout Trail that wanders along a basalt ledge just to the south. Immediately, we were privy to most of Bretz's lines of evidence. The layered basalt walls of the coulee channel soared 500 feet above us, the thin elongated blade of Umatilla Rock was prominent nearby, we walked on the bare surface of basalt, we passed by a wetland filling a pothole and two miles to the northwest, we could see the clean edge of Dry Falls, so much wider than Niagara, but silent.
In 1923, Bretz published a paper outlining his theory of a giant glacial flood carving the features of the area. "These remarkable records of running water...cannot be interpreted in terms of ordinary river action and ordinary valley development," he wrote. Established geologists dubbed his thesis an "outrageous hypothesis," yet he was invited to defend it in front of the Geological Society in Washington, DC in 1927. The debate centered on the fact that Bretz did not have evidence of a source of water voluminous enough to have effected such dramatic features on the landscape.
It is precisely this aspect of the scientific method that gives scientific inquiry its believability, especially in this age of conservative anti-science attitudes. Scientists care about evidence, tested and retested for accuracy. And scientists (generally) are willing to change their beliefs based on the revelation of new, reliable evidence. Even if a degree of uncertainty remains (we can't go back in time and watch the Grand Coulee being formed, after all), a preponderance of evidence leads to ever greater likelihood and probability that one explanation is most likely to be accurate. Importantly, though, in the scientific method the existence of uncertainty does not allow an alternate, evidentially unsupported theory to be believable.
Indeed, minds were changed as the process of scientific inquiry unfolded here at Grand Coulee.
In 1940, a geologist from Montana, Joseph Pardee, presented his findings about Glacial Lake Missoula. Like Bretz, Pardee had found elements of the landscape in western Montana that didn't fit well into a uniformitarian explanation-- terraced ancient shorelines on valley walls, giant current ripples and immense flood bars on valley floors-- which all pointed to the rapid draining of a huge body of water held in check by a glacial ice dam until it was unable to withstand the pressure of the water and gave way, allowing massive floods, sometimes with a peak flow rate more than 10 times the combined flow of all the present rivers of the world. His work provided the source for the megafloods that Bretz had found evidence for in the Grand Coulee. Combined and refined by much investigation in subsequent years since, Bretz' explanation of the Grand Coulee story was fully vindicated in 1965, when a group of geologists from the International Association for Quaternary Research toured the region and sent the now-83-year-old Bretz a telegram: "We are all now catastrophists."
The triumph of science that understanding Grand Coulee demonstrates is the polar opposite of the growing trend among right-wing conservatism toward anti-science attitudes.
The COVID-19 pandemic, occurring in the midst of the amplified political polarization stoked by rise and fall of Donald Trump, has opened a window into the anti-science mindset. As the virus emerged, epidemiological research produced guidance for the necessary public policy to mitigate the effects of the virus and shield as many people as possible from sickness and death. Unfortunately, conservative politicians and media seized on the legitimate fear engendered by the pandemic to brand the economic consequences of social distancing mandates as unfairly beneficial to people working in knowledge-driven fields like finance, tech and academia at the expense of those working in retail, service or manufacturing who couldn't transition to remote work. This appears to have enhanced the anger of many people who already tended toward a belief that it is a cultural shift in the direction of "elites" with greater diversity and education that has minimized their opportunities. Hostility toward the epidemiological guidance (masks, social distancing, vaccinations) emerged as a default coping mechanism that provided people holding the anti-elite mindset with a sense of certainty and control over what is in fact a frightening situation. Of course, the heightened susceptibility to emergent variants among the non-complying members of our society shows the ultimate folly of the anti-science response.
Likewise, the slow response to the urgency of the climate crisis has followed a similar course. Powerful entities whose profits are likely to diminish with the cessation of fossil fuel use initiated a smokescreen of disinformation designed to prey on the fears of those whose livelihood or economic position might be changed by a transition to renewable energy.
The tumult of our times seemed far away as Patty and I hiked the Umatilla Rock loop trail around it's namesake blade. Each of the pieces of evidence used by Bretz to formulate the interpretation of this landscape seems so logical now, in the presence of the preponderance of evidence that supports his conclusions. Understanding the evolution of this landscape greatly deepened our appreciation of the features we passed on our hike.
Thanks to the scientific method, we were able to enjoy the beauty of this place on this day, protected by vaccination and safety protocols enlightened by the hard work of scientists with a deep dedication to the "curiosity in thoughtful action" that brings us all to a fuller understanding of how it all works.
--David
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