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Jim Sheldon Brings To Life An Ice-Age Story
Montana Senior News, Feb. 2016/March 2016
If you think “The Erratics” sounds like the name for a rock group, you would be right—but probably for the wrong reason. The members of this non-musical band happen to feel more passionately about geology than The Rolling Stones.

They are a chapter of the Ice-Age Flood Institute (IAFI), a non-profit volunteer organization with a mission to advance science education. IAFI’s members do this through telling the story of the giant floods that scoured the Northwest 12,000 years ago.

Erratics, incidentally, is the name geologists have given to boulders carried by glaciers and deposited far from their place of origin. The next time you spot a mega-ton rock lodged in prairie grassland, you can safely assume it qualifies as an erratic.

When it comes to speaking to the public about erratics and the causes and consequences of earth-shaping floods, no one is more dedicated to the topic than Jim Shelden. A retired U.S. Forest Service geologist, Jim is president of the Glacial Lake Missoula chapter of the IAFI—aka “The Lakers.” As such, he spends many of his waking moments speaking everywhere from grade schools to retirement centers about these landscape-sculpting floods and how science affects our lives. Whatever the age of his listeners, he tells them, “To be a geologist you need to be observant and enjoy finding the answers to mysteries.”

One such mystery is the history of how Eastern Washington’s scarred and canyoned landscape was formed.

“At the end of the last Ice Age, we went from harsh glacial conditions to as hot as it is now. It took millions of years to build the ice caps, which melted in about 2,000 years. Each time a glacier funneled down from Canada into the Purcell Trench near Sandpoint, it dammed up the Clarke Fork River System,” explains Jim. “The body of water it created was called Glacial Lake Missoula (GLM). The first GLM had a flow rate equal to ten times all the rivers in the world and a volume of water equal to two Great Lakes stacked on top of each other. When that first ice dam collapsed, it sent a 2,000-foot-high wall of water to the West Coast traveling around 60 mph. It put a gigantic stamp on the face of the Northwest in an instant. The mud bank it created goes clear to the shores of San Francisco. And this cycle of glacial damming and collapse kept repeating itself till the end of the Ice Age.”

According to Jim, the starfish-shaped lake’s “body” covered the area of present-day Missoula while its “arms” stretched into valleys in five directions.

“Missoula is where the water starts,” he notes, “and Plains is the first place where all the arms of the lake were united. GLM was the biggest and first of the giant outburst floods recognized. There never has been a flood on earth in the order of magnitude of GLM.”

As part of The Lakers’ fundraising efforts, its members auction off trips to see visible evidence of a colossal lake that no longer exists. Not your usual eco-tour, these are 90-to-100-minute airplane flights from Arlee to St.Regis cruising at the same elevation, about 4200 feet, as GLM’s surface. Jim acts as tour guide, pointing out sites where the lake’s imprint and Ice-Age floods left their mark.

“The giant current ripples are our smoking gun proving the flood theory. We also see striations on hillsides, which are beaches or horizontal strand lines that never cross. The beaches have not changed in 10,000 years,” states Jim. “Some are even wide enough for fire trucks to drive on.”

In addition, The Lakers occasionally offer bus tours, which cost substantially less than the air flights. These field trips vary in length but all provide opportunities to see big-flood features. On September 23 and 24, The Lakers will host IAFI’s annual meeting in Missoula and offer a bus tour on the 24th.

“All the flood experts will be there along with members of IAFI’s 13 chapters,” says Jim. “The public is encouraged to attend.”

And lastly, free maps are available at the Montana Natural History Center detailing day-trip drives for your own geological tour of discovery.

“People come to Montana for lots of reasons aside from our national parks. Montana has super cool geology that is little known and under appreciated,” says Jim. “When visitors hear about GLM, they often want to do ‘the other thing.’”

The organization’s eco-tourism has found an especially eager audience among foreign visitors interested in seeing the results of the biggest flood ever recorded on the planet.

“GLM is better known internationally than in Montana. The Germans and Japanese are particularly fascinated by it,” says Jim. “They love science and anything Western.”

As a speaker for GLM, Jim focuses on answering the question: What good is science to the world?

“GLM provides a geological model to understand some aspects of climate change. It tells us the magnitude of things that can happen as a result of these huge climate swings. And we are going through one now,” warns Jim. “It’s warming very rapidly. There is no doubt the current climate change is heavily man-influenced.”

Remarkably, GLM has even taught us lessons about Mars.

“When we got the first pictures of Mars from the Viking Mapper, geologists knew Mars had GLM-type outbursts because of the flood features visible. We saw coulees, giant flood bars, and boulder fans,” recalls Jim. “It provided a big shortcut to figuring out the history of Mars and how the surface was formed. We know Mars had a lot of water at one time in its past because we knew what the signature of a giant outburst flood looked like.”

The GLM saga also comes with an intriguing human-drama angle. About a century ago J. Harlen Bretz, a little-known geologist at the time, proposed a radically different theory than was commonly accepted about how Eastern Washington’s topography was created. The leading geologists of Bretz’s day scoffed at his hypothesis that a cataclysmic water flow— rather than erosion over eons of time—had carved out the distinctive “Channeled Scablands.”

“Bretz spent 40 years trying to convince the Ivy-League science establishment that he was right. But it was not until the 1950s, thanks to advances in aerial photography and a better understanding of Ice-Age impacts, that his research and conclusions were vindicated,” says Jim. “At the age of 91, Bretz’s professional colleagues gave him their highest honor, the Penrose Medal. He finally received the recognition he deserved.”
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