Glacial Lake Wisconsin formed near the end of the last glacial period, about 18,000 to 14,000 years ago, when a lobe of the continental glacier blocked the normal flow of the Wisconsin River. Meltwater backed up against the ice and surrounding hills, creating a broad lake that spread across much of central Wisconsin. The lake’s life was brief. Around 14,000 years ago, the ice dam failed, releasing the water in a sudden outburst flood. Instead of slowly eroding the landscape, this surge tore thro

During the last Ice Age, six to seven million extra square miles of Earth were locked under massive ice sheets...most of it across Canada and the northern United States. Any cosmic impact in that era had a far greater chance of striking ice, not rock. Earlier theories claimed the ice melted over tens of thousands of years, but radiocarbon data compressed that timeline dramatically. Deglaciation wasn’t slow and steady... it was rapid, abrupt, and catastrophic. | The Randall Carlson