By these waters also the world of that time was deluged and destroyed....2 Peter 3:6
By TOM PAULSON
Potholes Coulee, near Quincy, is one of the most dramatic features left behind by the great floods. Click and drag photo to resize.
Seattle Post Intelligencer, June 26, 2006
QUINCY -- From the rocky terrace overlooking the small resort community of Crescent Bar clustered far below on the Columbia River, it becomes apparent just how bizarre a place this is and how stunningly violent its creation.
Not Crescent Bar.
We're talking about an event that took place 15,000 years before the development of the resort, an almost incomprehensible catastrophe that left its mark across the river.
"Over there on the other side, on West Bar, you can see the giant ripples," said Bruce Bjornstad, a geologist who has been studying the natural history of the Columbia Basin for decades.
The "ripples" are more like rolling hills when a person stands among them, since they are spaced about 350 feet apart and range from 20 to 40 feet in height. A huge flood, anywhere from 700 to 1,000 feet deep at this point, created the megaripples. The flood ripped across the region at the close of the last Ice Age.
Much of Eastern Washington's landscape is weird. The topography is unlike almost anywhere else on Earth, and in some locations bears so much similarity to the surface of Mars that NASA repeatedly has come here to test its Martian robotic rovers.
It is now recognized that the landscape here is strange largely because of the Ice Age floods. These weren't slow-moving floods caused by the gradual melting of the glaciers that, at the time, covered much of the land along the U.S.-Canada border.
No, the Ice Age floods tore through the Columbia Basin at something like 60 to 80 mph, sometimes reaching 1,500 feet in depth, scouring out canyons and eventually carrying most of the region's topsoil out into the Pacific Ocean. They typically lasted about a week, then were gone.
The evidence for this sudden, violent flooding is everywhere -- lake-size potholes created by the mortar-and-pestle grinding of rocks in whirlpools, steep basalt cliffs bordering wide, flat channels, thousands of "foreign" granite boulders that floods carried here from hundreds of miles away, and the megaripples.
But none of this was recognized until a geologist named J. Harlan Bretz came here to study this region known then as the "Channeled Scabland." In 1923, Bretz published his interpretation of what had carved the channels and wounded the land -- a huge, sudden flood.
"Nobody believed him," said Bjornstad, partly because the theory sounded distinctly biblical. The dominant paradigm in geology at the time, he said, was "uniformitarianism" -- the belief that geologic change happens slowly and steadily rather than by any sudden, major cataclysm.
Ephrata gravel fan. Click and drag photo to resize.
"All the geologists jumped on him over this," Bjornstad said. It likely didn't help that Bretz, a stubborn and taciturn man, basically told his colleagues to stuff it and refused to even debate the issue. Further, he said, Bretz couldn't explain where the water came from or what caused the sudden surge.
But the evidence continued to mount in his favor. Other scientists discovered other signs of flooding in Montana and determined that the surge of water came when the glacial ice dams holding huge lakes burst. In 1979, two years before his death, Bretz received the Penrose Medal, the highest honor in geology.
It's a great story of scientific discovery and perseverance. It's also not very well known by the public.
That's one of the reasons Bjornstad has just published a touring guidebook called "On the Trail of the Ice Age Floods." Though he works as a geologist on Hanford waste issues at the Pacific Northwest National Laboratory, the floods are his real passion.
Bjornstad is also a member of the Ice Age Flood Institute, a non-profit organization that has asked Congress to authorize an Ice Age floods trail system. The trails would trace the floods from Montana through the Columbia Basin out to the Pacific. The proposal, submitted by the National Park Service, has passed the Senate but remains stalled in the House.
"That's one of the reasons I wrote this book, to draw more attention to this," he said. Bjornstad turned toward the river and walked along the edge of the terrace toward a cairn. His GPS receiver started beeping, notifying him that he was close to his "geocache" -- though it was pretty obviously the cairn, in any case.
To add a little challenge to the hikes he describes in the book, Bjornstad has also provided a game of sorts. Hikers can use their GPS receivers to locate a geocache -- a plastic tub with a logbook, some information and all sorts of trinkets that visitors drop into it -- at some of the sites.
Bjornstad checked this one out, finding a pencil sharpener, silly putty, a figurine displaying two bunnies at a table, a carabiner and a dog dish. He closed it up and put it back in the cairn, with a few rocks on top. Lots of rocks around here.
"There used to be hundreds of feet of topsoil on top of this rock," Bjornstad said. If not for the floods, all of Eastern Washington would look more like the Palouse with its rolling hills of topsoil. "It was stripped away, most of it carried out into the ocean."
There was not just one Ice Age flood, Bjornstad emphasizes. Nobody knows precisely how many times these cataclysmic events hit the region, he said, but geologic evidence points to as many as 100 events over millions of years.
Scientists believe that the foreign boulders of granite, known as "erratics," likely were carried here on icebergs. Some are huge (one is more than 100 tons), so the icebergs had to be about 10 times larger to float that kind of weight.
The last flood, estimated to have struck between 13,000 and 15,000 years ago, may have had witnesses, Bjornstad noted.
Rattlesnake Mountain, near Hanford, is about 3,500 feet high. Erratics have been found on Rattlesnake up to 1,200 feet, he said, meaning the Tri-Cities was under at least that much water. The Native American name for that mountain, Bjornstad said, is "Laliik."
"It means land above the water," he said. "There's no water around here, so maybe their ancestors saw the last flood from the top of Rattlesnake. ... That would have been something to see."