How many glacial advances have occurred in Canada over the last 2.5 million years?

The correct answer is that there have been four major glacial advances in Canada over the last 2.5 million years. These glacial periods, known as glaciations, are part of the Pleistocene Epoch, which is characterized by repeated glacial and interglacial cycles.

During these glacial advances, large ice sheets spread over significant portions of Canada, altering the landscape through erosion, deposition, and other geological processes. Each advance contributed to the shaping of Canada's topography, including the creation of features like lakes, valleys, and moraines, which reflect the extent and influence of the glaciers.

The four key glacial advances that are typically recognized are the Nebraskan, Kansan, Illinoian, and Wisconsinan glaciations. The Wisconsinan glaciation, occurring most recently, had the most significant impact on the landscape we know today in Canada. Understanding this history is essential in recognizing how glacial activity has influenced current geography and ecosystems in the region.