Kennecott is an old mining town a few miles down the road from McCarthy. Today the abandoned copper mine and the still remaining town looks like a postcard of red buildings with white trim and machinery inside, built between a glacier and a mountainside. In the early 1900’s, this current National Historic Landmark site was found to have the richest known concentration of copper in the world. It was home to five mines, lots of miners, and a few families with children. As these children grew up in the mining town, their view down the hill was a massive glacier bed. The mines closed in the late 1930’s, and by the 2000’s, when the aging “Kennecott Kids” returned to their childhood home for a reunion, they were shocked to find a very different view than the one they remembered. The thick glacier bed was gone, and for the first time, they saw a whole mountain range on the other side of the remaining glacier.
In the photo below, Glaciology Summer School students are learning about the Kennicott (spelled with an “i”) Glacier in front of them and in the distance. The mounds of earth in the foreground at left are actually not mounds of dirt. They are mounds of ice. Where you see darker colored dirt, that is actually ice covered by just a thin film of dirt. Here you see where two glaciers, the Kennicott and the Root Glaciers, come together. As glacier flows merge as they move down the valley, rock and soil is gathered in a ridge between the glaciers. This is called a medial moraine. Moraines result in part from rocks falling onto the glacier from the mountains above, and they move along with the glacier. And as the glacier moves, it can also slowly grate the rock below, and bring them up to the surface. Rock cover of more than a few centimeters thick on a glacier is insulating, and will actually prevent melting under the rock cover. Therefore, as the ice around the thicker rock cover melts, mounds of ice covered by rock debris are left behind. As the glacier melts, even more rock inside and under the glacier becomes exposed, which continues the cycle, leaving behind more visible rock debris.
So, what you see below may not be white, but it is still part of the glacier. But here’s the big point here: just imagine the size and thickness of a glacier that can hide those mountains from view, and now imagine it decreasing to this point in just a few decades.
