Bringing to life the world's greatest lake

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By Kate Jackman-Atkinson

Neepawa Banner & Press

Arguably the world’s greatest lake, Lake Agassiz appeared to be little more than a frigid expanse of ice and water. But that initial impression proved to be far from reality when author Bill Redekop began looking beyond the surface. “It’s a special body of water,” he said of the lake.

“My impression going in was that [Lake Agassiz] was a lifeless body of water covered by the Laurentide Ice Sheet,” explained Redekop, “but if you looked towards the [Riding Mountain] escarpment, you would see an explosion of greenery, growing plants… The world was being reborn.” The land at the edges of the lake were home to big fauna, such as mastodons, wooly mammoth and bear-like species as tall as moose. “It was the land of giants,” said Redekop.

About 20,000 years ago, glacial Lake Agassiz covered most of what is now Manitoba and the Neepawa area was a special place within its ecosystem. In fact, the Neepawa area was so important to the lake, that the official launch of Redekop’s book, Lake Agassiz: The Rise and Demise of the World’s Greatest Lake, was held in Neepawa on Oct. 25, at an event co-hosted by the Beautiful Plains Museum and the book’s Winnipeg-based publisher, Heartland Associates.

A layman’s guide

Going into the three year project, Redekop knew little about the lake or its history, but was approached by the publishers, Barbara Huck and Peter St. John, about writing the book. An award-winning journalist, Redekop had worked with Huck and St. John on previous books. “I had written with them before and they pitched it,” he said. “Peter and Barbara have been educating readers about ancient geology for the past decade. [Most people] know so little about Lake Agassiz, yet it’s all around us,” he said of the motivation to bring the lake’s story to life.

Over the course of the book, Redekop takes the reader along his path of discovery, learning about the lake’s history and importance. While there is lots of information available about the lake, he explains that most of it is very scientific.  “My mission was to create a layman’s guide, so everyone can understand and know about Lake Agassiz,” he explained. He hopes that the book will serve as a framework, giving readers not just a basic understanding of the lake, but also giving those who want to learn more a foundation upon which to build.

A great lake has great beaches and part of the book follows Campbell Beach, which is one of the most prominent glacial beaches in the world. “Most are fragmented,” explains Redekop, adding that Campbell Beach, which stretches from the Manitoba-U.S. border to central Saskatchewan, is long and continuous. This beach, which is recognized with a sign at the Arden Ridge and Highway 16, is another reminder of the importance of Lake Agassiz to the area’s landscape. “It should be lauded with more than a sign,” he said.

‘Influenced so much’

For Redekop, the most surprising part of writing the book was discovering the lake’s importance. “It has influenced so much,” he said. Lake Agassiz is responsible for flattening the prairie, but also for the unique geological landscapes that can be seen across Manitoba; gravel in the Brandon area, sand in the Carberry area, silt in the Portage la Prairie area and finally, clay in the Winnipeg area.

While the geological information is interesting, the story needed a narrative and for Redekop, that was the story of the lake’s discovery. No one was looking to discover the existence of a giant glacial lake, but about 200 years ago, geologists noticed rocks which appeared to be out of place and began wondering how they got there.  For example, rocks from the Canadian Shield were found by Morden. While they investigated at a few different theories, geologist observed how mountain glaciers moved rocks down a landscape and began extrapolating from there about the existence of a giant glacial lake. In the 1890s, Warren Upham began mapping the phantom lake and published “The Glacial Lake Agassiz”.

Even the lake’s demise was dramatic, explained Redekop. The lake existed for about 6,000 years and when it finally receded north and connected with Hudson Bay, it was the biggest outburst of water in 100,000 years to flow into the oceans. This huge influx of water interrupted ocean currents and impacted the climate in Iceland and the United Kingdom for about 200 years.

In North America, the 10,000 year period where the glaciers were melting led to the rebirth of the continent. As the trees began to grow and wildlife made its home in the area, life began to flourish around the lake. Evidence of this remains and as part of his research, Redekop spoke to area residents with collections of artifacts related to this ancient period.  “It was almost like a climactic spring… Things were starting to grow, it was magical, life was returning,” Redekop explained.