Project 366 – Post No. 277 – Landslide

What is Project 366? Read more here.

A walk along the Whitemud Ravine and the North Saskatchewan River is a walk through time. The creek and the river are like time machines revealing past history by carving themselves slowly through earth revealing. The ancestral North Saskatchewan River flowed across the prairies for millions of years within a broad shallow-sloped valley named the Beverly Valley. Parts of that ancestral valley underlie the central part of Edmonton. About 27000 years ago a major glacier from the Canadian Shield advanced over the Edmonton region and ended up depositing thick sediment, completely burying Beverly Valley. The part of the river valley that is presently exposed in the City of Edmonton is only about 12000 years old. It was formed by the re-establishment of the regional drainage following the retreat and melting of the glaciers. This time, however, along a different path that the original Beverly Valley. Over the past 12000 years the North Saskatchewan River has carved down through the sediments deposited by the glacier creating today’s river valley. These days more than 60 million years of time are exposed in the geological records along the banks of the North Saskatchewan River, spanning the age of the dinosaurs to the arrival of man in North America. The signs of the ongoing erosion are everywhere along the Whitemud Ravine and while it may appear to be a slow process there are also signs that occasionally changes can happen in a matter of seconds. Several of the steepest banks along the creek show clear signs of landslides. Judging by the lack of vegetation on the slopes these landslides must have happened recently. Living along the upper edge of the ravine can be perilous as a 1999 landslides took several houses with it down.

May the curiosity be with you. This is from “The Birds are Calling” blog (www.thebirdsarecalling.com). Copyright Mario Pineda.